Rule to make player cast swarm pets untargetable with F8.

New npc_types field to allow any NPC to be untargetable with F8
Swarm pets will now be heal/buffable like live.
See change log for more details.

Note: The method used here to prevent
targeting is a hack but the only side
effect it turns affected NPC's names Yellow.

zone/npc.h

@@ -245,6 +245,7 @@ public:
 	void	AddLootDrop(const Item_Struct*dbitem, ItemList* itemlistconst, int16 charges, uint8 minlevel, uint8 maxlevel, bool equipit, bool wearchange = false);
 	virtual void DoClassAttacks(Mob *target);
 	void	CheckSignal();
+	inline bool IsTargetableWithHotkey() const { return no_target_hotkey; }
 
 	//waypoint crap
 	int					GetMaxWp() const { return max_wp; }