Make extended commands return defined flags

Instead of returning 0 or 1, we'll now use ECMD_OK or ECMD_TURN.
These have the same meaning as the hardcoded numbers; ECMD_TURN
means the command uses a turn.

In future, could add eg. a flag denoting "user cancelled command"
or "command failed", and should clear eg. the cmdq.

Mostly this was simply replacing return values with the defines
in the extended commands, so hopefully I didn't break anything.

src/do_name.c

@@ -1394,7 +1394,7 @@ call_ok(struct obj *obj)
     return GETOBJ_SUGGEST;
 }
 
-/* C and #name commands - player can name monster or object or type of obj */
+/* #call / #name command - player can name monster or object or type of obj */
 int
 docallcmd(void)
 {
@@ -1485,7 +1485,7 @@ docallcmd(void)
         donamelevel();
         break;
     }
-    return 0;
+    return ECMD_OK;
 }
 
 /* for use by safe_qbuf() */