ERT update 3: electric boogaloo.

Adds new ERT uniforms, and makes ERT members spawn with them.

![](http://puu.sh/aT10L/9e8c3adaa6.png)

Adds lockers with the new uniform, the old uniform, and the combat turtleneck to the ERT base. 

Adds new in-atmosphere ERT helmets and armor, and adds them to the ERT base. Their protection values match the tactical armor, without the slowdown.

![](http://puu.sh/aUjKA/b8ddf4079d.png)

Adds new ERT backpacks (sprites by PlasmaRifle) to the ERT base, removes the satchel from the ERT spawn.

![](http://i.imgur.com/FPf9yah.png)

Fixes some minor spelling errors.

This version is tested and verified, it should be ready for merge. Vote/discussion is here:
http://baystation12.net/forums/viewtopic.php?f=5&t=11082
26 for, 8 against, 3 abstain (one of them being myself).

I apologize for making so many PRs, but these merge conflicts are really horrible. If this could be merged as soon as possible, I would really appreciate it!