Clarify the quantum license (#1042)

* Clarify the license for files we have signoff on

* Update against the currently signed off files

* Remove unused and not clearly licensed headers

* Replace an #endif I accidentally removed while resolving merge conflicts

1 files changed, 264 insertions, 0 deletions

diff --git a/license_GPLv2.md b/license_GPLv2.md
new file mode 100644
index 000000000..b017086e9
--- /dev/null
+++ b/license_GPLv2.md
@@ -0,0 +1,264 @@
+The GNU General Public License, Version 2, June 1991 (GPLv2)
+============================================================
+
+> Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+> 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+
+Everyone is permitted to copy and distribute verbatim copies of this license
+document, but changing it is not allowed.
+
+
+Preamble
+--------
+
+The licenses for most software are designed to take away your freedom to share
+and change it. By contrast, the GNU General Public License is intended to
+guarantee your freedom to share and change free software--to make sure the
+software is free for all its users. This General Public License applies to most
+of the Free Software Foundation's software and to any other program whose
+authors commit to using it. (Some other Free Software Foundation software is
+covered by the GNU Lesser General Public License instead.) You can apply it to
+your programs, too.
+
+When we speak of free software, we are referring to freedom, not price. Our
+General Public Licenses are designed to make sure that you have the freedom to
+distribute copies of free software (and charge for this service if you wish),
+that you receive source code or can get it if you want it, that you can change
+the software or use pieces of it in new free programs; and that you know you can
+do these things.
+
+To protect your rights, we need to make restrictions that forbid anyone to deny
+you these rights or to ask you to surrender the rights. These restrictions
+translate to certain responsibilities for you if you distribute copies of the
+software, or if you modify it.
+
+For example, if you distribute copies of such a program, whether gratis or for a
+fee, you must give the recipients all the rights that you have. You must make
+sure that they, too, receive or can get the source code. And you must show them
+these terms so they know their rights.
+
+We protect your rights with two steps: (1) copyright the software, and (2) offer
+you this license which gives you legal permission to copy, distribute and/or
+modify the software.
+
+Also, for each author's protection and ours, we want to make certain that
+everyone understands that there is no warranty for this free software. If the
+software is modified by someone else and passed on, we want its recipients to
+know that what they have is not the original, so that any problems introduced by
+others will not reflect on the original authors' reputations.
+
+Finally, any free program is threatened constantly by software patents. We wish
+to avoid the danger that redistributors of a free program will individually
+obtain patent licenses, in effect making the program proprietary. To prevent
+this, we have made it clear that any patent must be licensed for everyone's free
+use or not licensed at all.
+
+The precise terms and conditions for copying, distribution and modification
+follow.
+
+
+Terms And Conditions For Copying, Distribution And Modification
+---------------------------------------------------------------
+
+**0.** This License applies to any program or other work which contains a notice
+placed by the copyright holder saying it may be distributed under the terms of
+this General Public License. The "Program", below, refers to any such program or
+work, and a "work based on the Program" means either the Program or any
+derivative work under copyright law: that is to say, a work containing the
+Program or a portion of it, either verbatim or with modifications and/or
+translated into another language. (Hereinafter, translation is included without
+limitation in the term "modification".) Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not covered by
+this License; they are outside its scope. The act of running the Program is not
+restricted, and the output from the Program is covered only if its contents
+constitute a work based on the Program (independent of having been made by
+running the Program). Whether that is true depends on what the Program does.
+
+**1.** You may copy and distribute verbatim copies of the Program's source code
+as you receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice and
+disclaimer of warranty; keep intact all the notices that refer to this License
+and to the absence of any warranty; and give any other recipients of the Program
+a copy of this License along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and you may at
+your option offer warranty protection in exchange for a fee.
+
+**2.** You may modify your copy or copies of the Program or any portion of it,
+thus forming a work based on the Program, and copy and distribute such
+modifications or work under the terms of Section 1 above, provided that you also
+meet all of these conditions:
+
+*   **a)** You must cause the modified files to carry prominent notices stating
+    that you changed the files and the date of any change.
+
+*   **b)** You must cause any work that you distribute or publish, that in whole
+    or in part contains or is derived from the Program or any part thereof, to
+    be licensed as a whole at no charge to all third parties under the terms of
+    this License.
+
+*   **c)** If the modified program normally reads commands interactively when
+    run, you must cause it, when started running for such interactive use in the
+    most ordinary way, to print or display an announcement including an
+    appropriate copyright notice and a notice that there is no warranty (or
+    else, saying that you provide a warranty) and that users may redistribute
+    the program under these conditions, and telling the user how to view a copy
+    of this License. (Exception: if the Program itself is interactive but does
+    not normally print such an announcement, your work based on the Program is
+    not required to print an announcement.)
+
+These requirements apply to the modified work as a whole. If identifiable
+sections of that work are not derived from the Program, and can be reasonably
+considered independent and separate works in themselves, then this License, and
+its terms, do not apply to those sections when you distribute them as separate
+works. But when you distribute the same sections as part of a whole which is a
+work based on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the entire whole,
+and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest your
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+
+In addition, mere aggregation of another work not based on the Program with the
+Program (or with a work based on the Program) on a volume of a storage or
+distribution medium does not bring the other work under the scope of this
+License.
+
+**3.** You may copy and distribute the Program (or a work based on it, under
+Section 2) in object code or executable form under the terms of Sections 1 and 2
+above provided that you also do one of the following:
+
+*   **a)** Accompany it with the complete corresponding machine-readable source
+    code, which must be distributed under the terms of Sections 1 and 2 above on
+    a medium customarily used for software interchange; or,
+
+*   **b)** Accompany it with a written offer, valid for at least three years, to
+    give any third party, for a charge no more than your cost of physically
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+    and 2 above on a medium customarily used for software interchange; or,
+
+*   **c)** Accompany it with the information you received as to the offer to
+    distribute corresponding source code. (This alternative is allowed only for
+    noncommercial distribution and only if you received the program in object
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+    above.)
+
+The source code for a work means the preferred form of the work for making
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+source code for all modules it contains, plus any associated interface
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+
+If distribution of executable or object code is made by offering access to copy
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+parties are not compelled to copy the source along with the object code.
+
+**4.** You may not copy, modify, sublicense, or distribute the Program except as
+expressly provided under this License. Any attempt otherwise to copy, modify,
+sublicense or distribute the Program is void, and will automatically terminate
+your rights under this License. However, parties who have received copies, or
+rights, from you under this License will not have their licenses terminated so
+long as such parties remain in full compliance.
+
+**5.** You are not required to accept this License, since you have not signed
+it. However, nothing else grants you permission to modify or distribute the
+Program or its derivative works. These actions are prohibited by law if you do
+not accept this License. Therefore, by modifying or distributing the Program (or
+any work based on the Program), you indicate your acceptance of this License to
+do so, and all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+**6.** Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the original
+licensor to copy, distribute or modify the Program subject to these terms and
+conditions. You may not impose any further restrictions on the recipients'
+exercise of the rights granted herein. You are not responsible for enforcing
+compliance by third parties to this License.
+
+**7.** If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues), conditions
+are imposed on you (whether by court order, agreement or otherwise) that
+contradict the conditions of this License, they do not excuse you from the
+conditions of this License. If you cannot distribute so as to satisfy
+simultaneously your obligations under this License and any other pertinent
+obligations, then as a consequence you may not distribute the Program at all.
+For example, if a patent license would not permit royalty-free redistribution of
+the Program by all those who receive copies directly or indirectly through you,
+then the only way you could satisfy both it and this License would be to refrain
+entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under any
+particular circumstance, the balance of the section is intended to apply and the
+section as a whole is intended to apply in other circumstances.
+
+It is not the purpose of this section to induce you to infringe any patents or
+other property right claims or to contest validity of any such claims; this
+section has the sole purpose of protecting the integrity of the free software
+distribution system, which is implemented by public license practices. Many
+people have made generous contributions to the wide range of software
+distributed through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing to
+distribute software through any other system and a licensee cannot impose that
+choice.
+
+This section is intended to make thoroughly clear what is believed to be a
+consequence of the rest of this License.
+
+**8.** If the distribution and/or use of the Program is restricted in certain
+countries either by patents or by copyrighted interfaces, the original copyright
+holder who places the Program under this License may add an explicit
+geographical distribution limitation excluding those countries, so that
+distribution is permitted only in or among countries not thus excluded. In such
+case, this License incorporates the limitation as if written in the body of this
+License.
+
+**9.** The Free Software Foundation may publish revised and/or new versions of
+the General Public License from time to time. Such new versions will be similar
+in spirit to the present version, but may differ in detail to address new
+problems or concerns.
+
+Each version is given a distinguishing version number. If the Program specifies
+a version number of this License which applies to it and "any later version",
+you have the option of following the terms and conditions either of that version
+or of any later version published by the Free Software Foundation. If the
+Program does not specify a version number of this License, you may choose any
+version ever published by the Free Software Foundation.
+
+**10.** If you wish to incorporate parts of the Program into other free programs
+whose distribution conditions are different, write to the author to ask for
+permission. For software which is copyrighted by the Free Software Foundation,
+write to the Free Software Foundation; we sometimes make exceptions for this.
+Our decision will be guided by the two goals of preserving the free status of
+all derivatives of our free software and of promoting the sharing and reuse of
+software generally.
+
+
+No Warranty
+-----------
+
+**11.** BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
+THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE
+STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM
+"AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
+PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+**12.** IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
+INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
+BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
+FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER
+OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.