Gas chamber and more

- Added shutter under/over/whatever HoP's desk and adds a button to
close it and the one under the window.
- Added a few more coins to maintenance.
- Adds hydroponics and a microwave to the prison wing. Gives those
leeches some work and food when shitcurity neglects them.
- Rewired the permabrig sector so the wiring doesn't go in the walls as
much and the two un-electrified windows of the lookout are actually
electrified.
- Added gas chamber. It's slow, dangerous, weird to use, and very likely
to get the executioner killed should the AI be rogue. It's perfect!
http://i.imgur.com/PhGCMud.png