Core/Spells: Fixed Shadowstep taking the caster out of combat while it shouldn't
Core/Spells: Fix Cheat Death formula
Core/Spells: Implement Periodic mechanics

Change behaviour of single target periodic aura ticks to be more blizzlike
Also add some missing handling of SPELL_AURA_MOD_CREATURE_AOE_DAMAGE_AVOIDANCE
Fixes Deep wounds and Chimera Shot Serpent
Remove an ancient hack with Drain Soul, spell id 100001 can now be deleted from spell_dbc table
Allows Rolling dot mechanics and allows DK's to roll diseases with pestilence,
see link for info:

http://forums.elitistjerks.com/topic/82503-frost-dps-in-333this-will-be-a-day-long-remembered/page-88
Merge pull request #12228 from Unholychick/patch_periodics

Core/Spells: Implement Periodic mechanics
Fix Warnings
Merge pull request #12240 from Unholychick/patch-3

Core/Build: Fix Warnings
Core/Handlers: Move a couple of logs to debug, they can appear without anything abnormal due to client latency
Merge pull request #12069 from Trisjdc/cheat_death

Core/Spells: Fix Cheat Death formula
Merge pull request #11739 from Golrag/master

Core/Spells: Fixed Shadowstep taking the caster out of combat while it shouldn't
DB/Quest: Fix some missing quest texts

By crysicle, closes #12167
Core/Vehicles: Fixed channeled spells being interrupted for passengers when vehicle moves
Core/NetworkIO: Adjust more packet throttling values

Ignore some opcodes that don't cause any trouble.
Remove old Allow/Disable Anti-DoS system since it's no longer required.