Scripts/Kelthuzad: move spells into spelldifficulty_dbc and cleanup
DB/Creatures: Added some data for dataless NPCs
Core/Chat: Fix valid chat links being handled as invalid

Fix a case where valid chat links would have been handled as invalid.
This happened if these conditions were true:
- the link was a profession and the link name started with the same name of the profession, like spell id 61120 in esES locale "Inscripción de la tormenta de maestro" with profession name "Inscripción"
- the profession name was the same for more than 1 locale available, like esES and esMX, or enUS and enGB

Restore memmove() instead of memcpy() wrongly replaced in 791130f6faf6294d2cb27bec409d7b4ee855243f , it's unsafe to use memcpy() with overlapping memory regions.
Core/Spells: fixed Throw Shield Visual and Clone Weapon
Partly revert 8edf6247c087884acd8c873a57c6f414e19091ec

This wasnt the correct way to fix trinkets and talents that should proc on periodic heals, as it also made talents that procs off spells with casttime proc...
Mentioned are affected, but there is a potential fix in:
https://github.com/TrinityCore/TrinityCore/issues/1896

NOTE to self: learn to use the proc_flag table
Core/CrashHandler: Add more informations about locals

Handle BasicType btChar and custom type std::basic_string<char,std::char_traits<char>,std::allocator<char> > (std::string).
This allows WheatyExceptionReport to log the text stored in char*, char[] and std::string.
Scripts/Ulduar: Fix uninitialized values

Fix uninitialized values in Ulduar script reported by Valgrind.
Merge pull request #11836 from Unholychick/patch-1

Partially revert 8edf6247c087884acd8c873a57c6f414e19091ec
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.
Core/ChatLog: handle chatlog options with extended logging system