Updated Ix_Aern_DRG

Added Spawn mechanics for Jailer of Faith and Ix'Aern Drk to match
retail. Added Ix'Aern DRG spawn mechanics for pets. Added on Mob death
check to spawn Ix'Aern DRG. Fixed Typos.
Merge pull request #673 from Turttle/Ix_Aern_drg

Updated Ix_Aern_DRG