Change NPCs to have their attack delay set in DB

This gives us a much more straight forward way of setting mob
attack delay with respect to live.

The attack_delay column is in 10ths of seconds, just like weapons are
The attack_speed is left for references for now.

zone/mob.h

@@ -1053,6 +1053,7 @@ protected:
 	Timer attack_dw_timer;
 	Timer ranged_timer;
 	float attack_speed; //% increase/decrease in attack speed (not haste)
+	int8 attack_delay; //delay between attacks in 10ths of seconds
 	float slow_mitigation; // Allows for a slow mitigation (100 = 100%, 50% = 50%)
 	Timer tic_timer;
 	Timer mana_timer;