Added an Atmospherics Hardsuit.

-Added sprites for the hardsuit to the right files.
-Added code in rig.dm for the Atmospheric Hardsuit.

2nd commit:
 -Added in-hand sprites for the atmospherics hardsuit.
-Dropped the radiation protection of the atmospherics hardsuit from 75, what engineering hardsuits have, to 50, what all other hardsuits have (except for CE).
-Added fire protection to the atmospherics hardsuit (equal to that of the CE and firesuits). 

The atmospherics hardsuit has less radiation protection than the engineering hardsuit, but offers fire protection instead.

Note: This pull request does not actually add the new suit to any map yet. I'll leave that decision up to mappers.

![atmohardsuitpreview](https://f.cloud.github.com/assets/3974988/879232/4ba71c9e-f924-11e2-8ad9-b9dd48806339.png)

![scrnshot1](https://f.cloud.github.com/assets/3974988/879138/918f5e30-f922-11e2-92a7-ca9ca60ded6f.png)
![scrnshot2](https://f.cloud.github.com/assets/3974988/879136/915d75d2-f922-11e2-964a-2159168f4827.png)
![scrnshot3](https://f.cloud.github.com/assets/3974988/879139/91962ddc-f922-11e2-8133-0e7e46f3a0e2.png)
![scrnshot4](https://f.cloud.github.com/assets/3974988/879140/91965596-f922-11e2-8381-08b907a74313.png)
![scrnshot5](https://f.cloud.github.com/assets/3974988/879141/9197723c-f922-11e2-88db-32235be3399d.png)
![scrnshot6](https://f.cloud.github.com/assets/3974988/879137/9176bc0e-f922-11e2-8fe9-2b6c4f14a4ea.png)
![scrnshot7](https://f.cloud.github.com/assets/3974988/879155/bff281a8-f922-11e2-9d0c-c50dd3caa2aa.png)