Argent squire/grunt fix

based on commit by  simlt
(https://github.com/A-Metaphysical-Drama/BloodyCore/commit/82dc9a28c78d8154d0f923a512ae88e7e63e833d)
Merge pull request #1 from TrinityCore/master

merge
Scripts/Kelthuzad: move spells into spelldifficulty_dbc and cleanup
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/server/game/Entities/Unit/Unit.h
	src/server/game/Handlers/MailHandler.cpp
	src/server/game/Handlers/NPCHandler.cpp
	src/server/game/Server/WorldSession.h
Fix argent squire/grunting mailbox
Make Cyclone and faerie fire unable to pierce cyclone and banish
Merge branch 'master' of git://github.com/TrinityCore/TrinityCore

Conflicts:
	src/server/scripts/Spells/spell_generic.cpp
Merge branch 'master' of git://github.com/TrinityCore/TrinityCore
Merge branch 'master' of git://github.com/TrinityCore/TrinityCore
Core/Chat: Fix AddonMessaging and logging
Fix SPELL_AURA_MOD_AOE_AVOIDANCE

There is not a single spell using this aura, but now it works :)
Merge pull request #11849 from Unholychick/master

Fix SPELL_AURA_MOD_AOE_AVOIDANCE
Core/Movement: Fix LoS issue of NPCs chasing targets

Add Line of Sight checks to WorldObject::GetNearPoint(), fixing to TargetedMovementGenerator not reaching a point with valid LoS to the target and MotionMaster::MoveKnockbackFrom() knocking creatures inside walls.
Remove unused code.
.cheat god should also affect on falling damage.
Fix SPELL_DAMAGE_CLASS_NONE unable to crit

Corrected logic mistake where switch fallthrough was intended (or should have been).
Fixes the following.
// Earth Shield
// Lifebloom Final Bloom
// Divine Hymn
// Item - Bauble of True Blood 10m
// Item - Bauble of True Blood 25m
Merge pull request #11858 from Dimitro/master

.cheat god command should also affect on falling damage.
Merge pull request #11857 from Unholychick/master

Core/Spells: Fix SPELL_DAMAGE_CLASS_NONE unable to crit
Core/Logging: store loggers in cache correctly
Merge pull request #11840 from Rochet2/AddonMessaging

Core/Chat: Fix AddonMessaging and logging
Core/CrashHandler: Log GetLastError() id if no description is found

Log the System Error id returned by GetLastError() in case FormatMessage() doesn't find a proper description for that message.