Make storage I/O configurable

Currently, all storage takes input on one side and outputs on the other. This _really_ hinders nice builds. Also, it's not very much realistic; irL warehouses can be used from any side for any purpose.
The overall game is pretty much realistic - I managed to starve everyone to death in my first game; I'm quite certain I could do that in reality, too.

This would be a wonderful higher priority update as only having one side currently for in and one or out makes it extremely difficult. The balancers are four sided and customizable, Storage should be too! Thanks!