Add some Follow stuff to lua

You can also disallow following code from allowing the NPC to run if
they're far enough away

zone/lua_npc.h

@@ -92,6 +92,9 @@ public:
 	bool IsGuarding();
 	void AI_SetRoambox(float dist, float max_x, float min_x, float max_y, float min_y);
 	void AI_SetRoambox(float dist, float max_x, float min_x, float max_y, float min_y, uint32 delay, uint32 mindelay);
+	void SetFollowID(int id);
+	void SetFollowDistance(int dist);
+	void SetFollowCanRun(bool v);
 	int GetNPCSpellsID();
 	int GetSpawnPointID();
 	float GetSpawnPointX();