Another bunch of simplemob fixes

-Fixes the issue with mob AI not getting properly disabled under player control.
-Fixes mob eye overlays not respecting the mob's scaling setting.
-Fixes the movement cooldown on logged in ridable mobs.
-Fixes direwolf not getting belly icon when resting.
-Makes the mob icon fullness check account for the mob's own size as well.

code/modules/ai/ai_holder_disabled.dm

@@ -5,7 +5,7 @@
 
 // If our holder is able to do anything.
 /datum/ai_holder/proc/can_act()
-	if(!holder) // Holder missing.
+	if(!holder || (holder.client && !autopilot)) // Holder missing or occupied.
 		manage_processing(AI_NO_PROCESS)
 		return FALSE
 	if(holder.stat) // Dead or unconscious.