[z2164] Use Pool system for BG buff

Drop not required manual handling of BG-Objects

Signed-off-by: Schmoozerd <schmoozerd@cmangos>

(based on commit [12242] - cd9563c)

(based on commit [s1796] - b7dbf5a)
[z2165] Fix Extracting for cmake.

(based on commit [12243] - a4b3bc5)

(based on commit [s1797] - ce57530)
[z2166] Add positive exception for spell 18153

(based on commit [12244] - eabba37)

(based on commit [s1798] - 352b192)
[z2167] Change gameobject_template storage to SQLHashStorage

Also use direct-data iterators instead of lookup-entry calls

(based on commit [12245] - 1cd91c6)

(based on commit [s1799] - 1c0de2f)
Merge branch 'master' into testing