Update to how bonuses are calculated in chance to hit code to be

consistent across all relevant effects (treating avoidance
and hit chance bonuses equally).
Rule ArcheryHitPenalty will now calc correctly (Was doing basically nothing)
New field npc_types 'Avoidance' (add avoidance bonus to npc)
Rules for setting min / max chance to hit

utils/sql/git/required/2014_07_10_npc_spells.sql

@@ -1,6 +1,7 @@
 -- npc_types
 ALTER TABLE  `npc_types` ADD  `ammo_idfile` varchar( 30 ) NOT NULL DEFAULT  'IT10' AFTER `d_meele_texture2`;
 ALTER TABLE  `npc_types` ADD  `ranged_type` tinyint( 4 ) UNSIGNED NOT NULL DEFAULT  '7' AFTER `sec_melee_type`;
+ALTER TABLE  `npc_types` ADD  `Avoidance` mediumint(9) UNSIGNED NOT NULL DEFAULT  '0' AFTER `Accuracy`;
 
 -- npc spells
 ALTER TABLE  `npc_spells` ADD  `range_proc` smallint(5) NOT NULL DEFAULT '-1';