Add CHT sequence

This sequence performs "Cursor Forward Tabulation <n> tab stops", which
although is not present in vt100 or vt102, xterm accepts it.
---
 st.c |    5 +++++
 1 file changed, 5 insertions(+)

1 files changed, 5 insertions, 0 deletions

diff --git a/st.c b/st.c
index b7dfd55..b9bab29 100644
--- a/st.c
+++ b/st.c
@@ -1226,6 +1226,11 @@ csihandle(void) {
                 DEFAULT(escseq.arg[1], 1);
                 tmoveto(escseq.arg[1]-1, escseq.arg[0]-1);
                 break;
+        case 'I': /* CHT -- Cursor Forward Tabulation <n> tab stops */
+                DEFAULT(escseq.arg[0], 1);
+                while (escseq.arg[0]--)
+                        tputtab();
+                break;
         case 'J': /* ED -- Clear screen */
                 sel.bx = -1;
                 switch(escseq.arg[0]) {