Expands medbay with new rooms.

This is a neat little expansion I did to medbay based on requests in the thread. Adds the following rooms:
1. A backup generator room, with chargers for cyborgs
2. A diagnostic medicine room, to meet in
3. A psych ward for braindead patients, with good vending machines
4-5. Two Xenomedical rooms, designed to treat Vox and Plasmaman patients
6. Medical escape pod

Do not merge yet. Escape pod has areas defined but won't be coded until we're sure we want another one.