Soap changes + bugfix

### soap update

* Soap no longer has infinite uses and its icon will shrink as it is used up

![soapicons](https://f.cloud.github.com/assets/4912533/2454569/559bba6e-aeed-11e3-9a13-b2a51726b22a.png)

* Box of soap bars added to custodial closet
* Box of soap bars added to janitorial supply crate
* Soap moved to its own .dm and .dmi

### bugfix
* Pill bottle box actually uses the sprite available for it now