The `spell_group` table
Table used to group spells for varius checks in the core. One spell may be added to many groups, but can occur in one group only once.
Description of the fields
Rules of assigning id:
- if group is going to be used in core code, use first avalible entry below 1000 and add enum value to SpellGroup enum in SpellMgr.h
- if group is not going to be used in core code, use lowest avalible entry higher than 1000
SpellId from Spell.dbc or spell_group id prefixed with "-". If spell is added to spell_ranks, spell_id has to be first rank of that spell.