[Ready] Hospital upgrades

This adds a hospital-bed itemgroup and has it spawn in hospital beds (simulating patient belongings, paperwork, etc).  Removes beds' CONTAINER flag so we can see the stuff (and the prison contraband too, incidentally)--dunno if that messes up vehicles.  Ian, commentary?

Also adds low chance of bionics_common spawns in the hospital lab and two of the surgeries.  (The Mr Stem Cell is only in one surgery, so I thought partial-coverage was OK.)

Bed change reverted, items now on floor.  Whenever you're ready, folks.