Implement _NET_DESKTOP_NAMES, this one was a bit tricky since thespec

says that a pager can change the property at any time (most need a
clientmessage). So deal with property updates.

Needed to shuffle some of the other code around since we can't just use
shortcut_to_name[] everywhere now.

ok okan@

conf.c

@@ -225,7 +225,6 @@ conf_clear(struct conf *c)
 		xfree(ag->class);
 		if (ag->name)
 			xfree(ag->name);
-		xfree(ag->group);
 		xfree(ag);
 	}