Toxin mixing room gas monitor

The toxin mixing room now has a monitor computer to allow scientists to check gas composition, pressure, and temperature inside both sections of the gas chamber.
Added a few more warning signs. Made a sign outside the HoP's office stop lying by re-electrifying the window grills.
Also warning stripes.
Catwalks too.
Merge pull request #6825 from PsiOmegaDelta/Toxins

Toxin mixing room gas monitor