Added an Atmospherics Hardsuit.
-Added sprites for the hardsuit to the right files.
-Added code in rig.dm for the Atmospheric Hardsuit.

The stats of the Atmospherics Hardsuit are equal to those of the Engineering Hardsuit, so the differences are purely cosmetic in nature. It lets mappers distinguish between hardsuits assigned to Engineering and Atmospherics.
-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).
Merge pull request #1045 from Ricotez/master

Added an Atmospherics Hardsuit.