Fix loading some save games prior to 88b4b1e

When creating the multi_use_object action in operating_theatre.lua
use the name surgeon1 in the callback as was the case prior to
88b4b1e. Unfortunately save games created between 88b4b1e and this
fix may be broken.

Similarly other callbacks in operating_theatre needed to be changed
to support their pre 88b4b1e environment.
Merge pull request #395 from TheCycoONE/issue380

Fix loading some save games prior to 88b4b1e