[0495] Added script for creature 10299 in Blackrock Spire

* Added support for event in Blackrock Spire of Scarshield Infiltrator
morphing into Vaelan
Source: http://www.youtube.com/watch?v=VVxOPiDVwNQ
This closes #411
[0496] Update HP of creature 8516 in Razorfen Downs

* Fixed stats for creature 8516 (Belnistrasz) in Razorfen Downs because
he was too weak preventing the players to defend him successfully in the
quest "Extinguishing the Idol"
Source: UDB