Merge pull request #9772 from Mihapro/4.3.4

Core/SpellSysten: Reimplement custom spells (spell_dbc & spelleffect_dbc)
Merge pull request #9780 from Mihapro/4.3.4

Core/Players: Create default pet for new hunter characters
DB/Spells: Fixed server startup after 492c695021a220.
Core/StatSystem: Implemented mastery.
Merge remote-tracking branch 'upstream/4.3.4' into 4.3.4