Fixed fire alarm in virology #3875
Fixed random pixel on glasses #3872
Fixed welder issue #3888. Plus explored further issue with welder, fixing it. Small logic optimization.
Fixed firelocker icon not being updated with welded overlay, even so they have been welded
Welding interaction with closets was reworked, almost all secure closets except for detective's, barternder's now work with welding same way as closets/crates.
Coffins, and wooden closets of any kind can no longer be welded shut.
Clean up of some code using src as reference, and :