Scripts/Kelthuzad: move spells into spelldifficulty_dbc and cleanup
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 :)
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
Core/Logging: store loggers in cache correctly
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
Fix Sweeping Strikes damage
Scripts/Ruby Sanctum: Fixed Onyx Flamecallers not aggroing players once pathing ended.
Scripts/Ruby Sanctum: Fixed Halion engaging combat outside of his Flame Ring.
Core/GameObjects: Fix crash with Summoning Ritual GOs

Fix a crash happening with GAMEOBJECT_TYPE_SUMMONING_RITUAL GameObjects if a Player clicked on the GO, logged out and let another Player click on it.
Issue added in 464c0c16116dfd22b3c104165ce6edd7b7f4a3d4
Fixes #11856
Scripts/ZulGurub: clean up the code and remove old hacks
Scripts/Commands: Ensure gameobject template is valid from .gob add temp [...]

As per Aokrome's spamming. "Avoids false positive logs"
DB/Item: Fix Essence of the Pure Flame scaling

By gecko32, closes #1925
Core/Spells: Fixed players being able to mount with all transform auras

Closes #11852
Scripts/Commands: Fix .mmap loc wrong coordinates

Fix .mmap loc command printing swapped x and y tile coordinates
Scripts/Commands: ".modify speed" targets current Player by default

Allow ".modify speed" command to target current Player if there is no target or if the selected Unit is a Creature.
This behavior could be extended to other commands that require target Players.
Scripts/Commands: Fix memory leak in ".gobject add" command

Valgrind log:
 158 (104 direct, 54 indirect) bytes in 1 blocks are definitely lost in loss record 24 of 73
 at operator new(unsigned long) (vg_replace_malloc.c:319)
 by GameObjectModel::Create(GameObject const&) (GameObjectModel.cpp:152)
 by GameObject::Create(unsigned int, unsigned int, Map*, unsigned int, float, float, float, float, float, float, float, float, unsigned int, GOState, unsigned int) (GameObject.cpp:237)
 by gobject_commandscript::HandleGameObjectAddCommand(ChatHandler*, char const*) (cs_gobject.cpp:155)