HoS Beret Addition

Adds Nienhaus's HoS Beret sprite as the alternative HoS Hat. The Drill hat is currently in the back burner in this PR however if this PR is merged I will set up a forum poll to determine which hat style people prefer.

For reference: https://github.com/tgstation/-tg-station/pull/5690

Images
With current jacket
![screenshot 2014-11-10 01 01 32](https://cloud.githubusercontent.com/assets/6595389/4968105/664aa51e-6833-11e4-9b9e-053d54e4907b.png)

With alternative jacket
![screenshot 2014-11-10 01 01 16](https://cloud.githubusercontent.com/assets/6595389/4968106/71042a0c-6833-11e4-9b4e-2cf09a9eff55.png)