some NPCID updates, minor clean-up & fixes

-started updating NPCIDs. All conquest NPCs, HELM points & field manuals are done. Left to do are ground tomes, treasure chests/coffers, npc_dummies, and regular zone NPCs.
-included Xipies suggested fix for Chululu.
-I've verified that this pull request resolves issues #: 286, 309, 398, 471, 479, 480, 481 & 492.