Fixes and tweaks to surgery

Created by: 9600bauds

Fixed not being able to use screwdrivers as ghetto surgery tools. (fixes #7612 (closed)) Added an error message when trying to use surgery to fix a bone fracture in a very damaged limb. This is to prevent the "bone explodes immediately after being mended" syndrome. (fixes #7615 (closed)) Will no longer place items on operating tables, which was really annoying because it would end up in accidentally dropping your surgery tools under the patient. If you really want to place an item on top of the operating table for some reason, you can throw it on top instead.