Security Sprite updates.
Replaces all instances of the old Swat and riot sprites with Validsalad's new ones
Replaces Sechailer's with Officer, Warden and HoS versions code and Sprites wise (Sptires by Validsalad again)
The officer gas mask is gas/sechailer, the warden's is gas/sechailer/warden and the HoS's is gas/sechailer/hos
Merge pull request #2094 from RobRichards1997/19/12/2013-Sec-see-Sec-Sprites

Security Sprite updates.