Core/Objects: Changed `playercreateinfo_spell` and `playercreateinfo_spell_custom` to use race and class masks.

Specifying a race mask of zero will provide the spell to every race.
Specifying a class mask of zero will provide the spell to every class that the race can be.

Note: As the SQL truncates `playercreateinfo_spell`, all your "custom" additions will be gone.