Core/Summons: Implement summon groups system to be able to summon multiple NPCs at once without need of hardcoding the positions. Almost all hardcoded positions can now be moved to DB.

Thx to @Shauren for his help.
Merge pull request #9280 from horn/summons

Core/Summons: Implement summon groups system to be able to summon multiple NPCs at once without need of hardcoding the positions. Almost all hardcoded positions can now be moved to DB.
Core: Fix a comment in LoadConfigSettings

Closes #9292
Script/Quest: The Lonesome Watcher (12877)

Closes: #9185
See: http://www.youtube.com/watch?v=ylZRMu9CIMw
Core/Spells: Define SPELL_ATTR6_PRINT_SPELLNAME

(Can't think of a better name/description)
Core/Spells: Implement TRIGGERED_IGNORE_EQUIPPED_ITEM_REQUIREMENT to allow ignoring equipped item requirements on triggered casting
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore