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