Mute Changes

- R_MOD is now needed to mute players.
- Admins/mods/mentors can now be muted. The first two can unmute
themselves, the third cannot.
- Global OOC mute now applies to mentors as well, but not to admins or mods.
- Global Deadchat mute still only applies to regular players.
- Mods using DSAY will show up as MOD instead of MENTOR.

code/modules/admin/topic.dm

@@ -1015,7 +1015,8 @@
 				return
 
 	else if(href_list["mute"])
-		if(!check_rights(R_ADMIN))	return
+		if(!check_rights(R_MOD))
+			return
 
 		var/mob/M = locate(href_list["mute"])
 		if(!ismob(M))	return