Port PROX_AGGRO from EQMacEmu

If this ability is set, the NPCs will continuously add things to their
hate list while their engaged. If it's not set (default) they won't,
which is what the vast majority of NPCs do on live.

zone/common.h

@@ -138,7 +138,8 @@ enum {
 	IGNORE_ROOT_AGGRO_RULES = 42,
 	CASTING_RESIST_DIFF = 43,
 	COUNTER_AVOID_DAMAGE = 44,
-	MAX_SPECIAL_ATTACK = 45
+	PROX_AGGRO = 45,
+	MAX_SPECIAL_ATTACK = 46
 };
 
 typedef enum {	//fear states