Command repeating by using cmd queues

This replaces the old pushq/saveq arrays (which were used to save
the keys pressed by the user for repeating a previous command)
with a new command queue.  This means there's no hard-coded limit
to the saved keys, and it can repeat extended commands which are
not bound to any key.

src/engrave.c

@@ -969,7 +969,7 @@ doengrave(void)
                    && (!Blind || oep->engr_type == BURN
                        || oep->engr_type == ENGRAVE)) {
             c = yn_function("Do you want to add to the current engraving?",
-                            ynqchars, 'y');
+                            ynqchars, 'y', TRUE);
             if (c == 'q') {
                 pline1(Never_mind);
                 return ECMD_OK;