[squashme] Pipeworks

[SwissalpS]

• adds pipeworks support for the railguns, can be filled from all sides except the front

• adds icon in inventory to indicate what ammo is needed

• does not block other items than ammo to be added to inventory

closes #21

[SwissalpS]

Edit: one question, does this also make railguns work with injectors?

yes, in and out, even through the muzzle ;)

[dennisjenkins75]

LGTM.