Core/Player: Fix a query that was wrongly deleting items

CHAR_DEL_ITEM_INSTANCE deletes by item guid but in Player::DeleteFromDB the guid being used was player's guid.
That means that if player with guid 100 was deleted, the item with guid 100 would also be deleted. This item could or could not belong to the player.

Closes #8883
Closes #9136

Thanks to @vlad852 for finding the issue
DB/Misc: Fixup quest Hot On The Trail (A:24849 H:24851)
Fix up previous commit.
Core: Fixed some compile warnings
Core: Clean up whitespace, and remove a silly warning in boss_lurker_below.cpp
Core: More clean up whitespace
typo
Core/Accounts: sessionkey field in account table is only a temporary storage to pass data from authserver to worldserver and should only be used as such. Clearing sessionkey from database after a successful login to prevent possible exploits.
Core/Auth: Reverted part of fb43a92cc2aaffab42efebf025b6a12c01af8fde - session key is still needed after logging in to be able to switch realms
Core/AI: Fixed merge error
Core/Players: Fixed crash when mute expired while player was ingame
Merge pull request #9166 from thomas33/typo

Core/Scripts: Coding style
DB/Triggers: Added areatriggers in Shadowfang - when you'll try to jump out of the dungeon walls, you will be teleported
Core/DBLayer: Avoid a crash when calling mysql_get_server_version if connection was not open
DB/Quests: Fix quest The Collapse and Deploy the Shake-n-Quake

Ref #1005
Ref #2034
Ref ae307048475ff14863d5a
Closes #3595
Script/Quest: Kodo Roundup

Closes #943
Core/SAI: Rewrite SmartAI::RemoveAuras in a safer way
Core/Spells: Fix cooldown problems for Val'anyr, Hammer of Ancient Kings
Closes #9162
Core/Objects: Rewritten UpdateMask class to perform bit operations faster at the cost of higher memory use and moved building the mask for packet to a separate method.

Closes #9127
DB/Creature: Fix Onyxian Lair Guard equipment