Suggestion/bug report - clear lockers/plastic walls

Created by: Killette2

This is also a bug report, if you try to use plastic sheets on a girder as plastic registers as a mineral, it deletes the girder and uses the plastic rather than making a plastic wall. I think one would be neat.

I also think we should be able to have semi-see through plastic lockers. Thin lockers made of plastic that you can see through as to what's inside, as raincoats you can make with plastic are see through.