Plugsuits

Adds three new costumes, a red (Asuka), blue (Shinji), and white (Rei) plugsuit.
All three items have no spawn point, meaning they can only be admin spawned.
Plugsuits use the suit slot and function the same as the clown and mime's costumes, meaning they have no effects other than cosmetics.
![plugsuits](https://cloud.githubusercontent.com/assets/8682093/4177270/b22e6d60-3630-11e4-9fcf-adc7a17c64fa.png)

Modifies:
suits/miscellaneous.dm
mob/items_lefthand.dmi
mob/items_righthand.dmi
mob/suit.dmi
clothing/suits.dmi