Core/Misc: Get rid of some warnings.
Core/Misc: Kill few more warnings.
DB/Misc: Random fixes/error fixes
Core/Group: Update enum GroupType
DB/Misc: Couple more fixes

closes #13112
closes #13115
Scripts/CoS: implemented Infinite Corruptor, improvements in instance script and Meathook converted to BossAI

Guardian of Time should have some text, but I have not found anything in sniff. Also the whole event needs to be rewritten and improved.
Remove mount vendor cpp script
Merge pull request #12927 from MitchesD/misc_3

Scripts/CoS: implemented Infinite Corruptor, improvements in instance sc...
Core/Quests: Only prompt the player to take the next quest in a chain if he meets the conditions for that quest.
Core/Skills: Fix rogue's lock picking

Fixes #12677
Closes #13111
Core/NetworkIO: Set non blocking mode on sockets properly
Core: Fix warning
DB/Gameobject: Allow to target 2 gameobjects

Closes  #13093, closes #13094
Core/Misc: Added const modifier to MessageBuffer::Write parameter
Core/WorldSocket: Refactored client packet header check
DB/Quest: The Demoniac Scryer

Closes # 2610

Script for http://www.wowhead.com/quest=10838/the-demoniac-scryer