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/o_init.c

@@ -851,8 +851,7 @@ doclassdisco(void)
             }
         }
         /* get the class (via its symbol character) */
-        c = yn_function(prompt, discosyms, '\0');
-        savech(c);
+        c = yn_function(prompt, discosyms, '\0', TRUE);
         if (!c)
             clear_nhwindow(WIN_MESSAGE);
     } else {