Revert "[TW224] - Core/Spells: Attempt to solve the issue with spells cast while in gcd getting stuck (i.e Cold Snap, Shadowform, Misdirection, Tricks of the Trade... more can be added)"

This reverts commit f506d8f2c1c5abfd6a79d03e7693fff7a8ca10df.
[TW258] - Core/Scripts: Implement the Conqueror of Ulduar, thanks to @UnholyChick
Merge branch 'master' of https://github.com/TrueWoW/TrinityCore