Core/Spells: Fixed Shadowstep taking the caster out of combat while it shouldn't
Core/Spells: Define and implement SPELL_ATTR7_NO_PUSHBACK_ON_DAMAGE
Fixed SendAddonMessage issue.

This fixes GM's not being able to send/receive addon messages through the whisper channel while accepting whispers are turned off.
Core/Players: Fix haste rating formulas. They're supposed to be the addition, not the multiplication of all available bonuses

- This change matches client formulas
Core/CreatureAI: Implement CreatureAI::TalkToMap for all your map-wide talking needs. Could also replace Battleground::SendChatMessage
Core/Spells: Fix Cheat Death formula
Core/SAI: Clear UNIT_STATE_EVADE immediately if we're about to follow a target on EnterEvadeMode (MoveFollow does not clear evade)
Core/PetAI: Pet's owner should NOT enter combat when the pet attacks/enters combat
Core/Spells: Players with active pets count as if they were players in combat against spells with SPELL_ATTR1_CANT_TARGET_IN_COMBAT
Core/Misc: Removed remnants of old db threading model
Core/Vehicles: Set proper power type using PowerDisplay.dbc

Original commit by Xfurry - cmangos/mangos-wotlk/bef8c99cc07c96d4e2f45e0ff6bc107068555ffb
DB/Quest: Fix Gambling Debt

By dr-j, closes #12092
DB/Creature: Fix Crazed Mana Surge

By dr-j, closes #11998
Merge pull request #12018 from Foereaper/master

Core/Misc: Fixed SendAddonMessage issue.
Merge pull request #12083 from Trisjdc/pet_combat

Core/PetAI: Pet's owner should NOT enter combat when the pet attacks/enters combat
Merge pull request #12076 from Trisjdc/even_more_sai

Core/SAI: Clear UNIT_STATE_EVADE immediately if we're about to follow a target on EnterEvadeMode
Core/Misc: Remove Unit::Get* wrappers for ObjectAccessor::Get*
Core/Achievements: Fix ACHIEVEMENT_CRITERIA_TYPE_GET_KILLING_BLOWS
Core/Spells: Nitro Boost should not fail in dungeon maps
Merge pull request #12107 from Trisjdc/nitro_jump

Core/Spells: Nitro Boost should not fail in dungeon maps