DB/Creature: Delete some double spawns

Updates #1515
DB/Reputation: Fix Oracle and Frenzyheart Tribe reputation

Closes #11106
Core/LFR: Fix a theoretical error with item_level
Despite the check never happening (player->GetAverageItemLevel() < 0 is impossible), it is more efficient.
Also improves codestyle consistency. Original fix by @emsy.
Merge pull request #11616 from Ascathor/master

Core/LFR: Fix a theoretical error with item_level
DB/Creature: Correct Felmist gas cloud model
Misc Move file to proper place
Core/Chat: Fix BuildChatPacket calls so scripts that use OnPlayerChat can actually change the text

Closes #11625
DB/Misc: Fix some startup errors

Updates #11587
DB/Misc: Fix more startup errors

By Fateswhisper and me. Updates #11587
NOTE: ref "Missing WDB data." we have more of those and since i don't fill WDBVerified it's correct.
DB/Misc: Coding standards
DB/Creature: Commander Hogarth must be male human.

Closes #11581
DB/Quest: Update OfferRewardText for quest 396

Notice: i realize of the typo, but wowhead shows that text, if anyone have a prof of it's wowhead typo i will fix it.
Closes #11534
DB/Quests: Corrected a typo, because typos suck.
DB/Creature: Misc fixes to Thomas Yance and guards around

Updates: #3905
DB/Creature: Remove random movement from "Webbed Creature"

By baric, closes #9607
DB/Creature: Add trigger flag to Multiphase Disturbance

Updates #6279
DB/Creature: Fix db errors added on fd8a669
DB/Conditions: Fix gnome mount vendors for non-gnomes
DB/Quest: Fix Corrosion Prevention

By untaught closes #11630
Core/Group: Fix online state when member logs out