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/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
Scripts/Krystallus: converted to EventMap, removed useless code
Merge pull request #12082 from MitchesD/misc_2

Scripts/Krystallus: converted to EventMap, removed useless code
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*