[12756] Implement Battleground scores storage system

Close #138

Signed-off-by: Xfurry <xfurry@scriptdev2.com>
[12757] Add Shaman/Warrior flurry spell chains

Fixes flurry procs related to spell_proc_event table. Closes #392

Signed-off-by: Cala <calaftp@free.fr>
[12758] Add missing SQL update in previous commit
Thanks evil.at.wow for pointing.
[12759] Revert [12757]

Spell chain for these warrior/shaman talents were already added in WotLK core.
[12760] Extend pvp team indexes to global use

Close #139

Signed-off-by: Xfurry <xfurry@scriptdev2.com>