Patched PDA scanner to be more useful

PDA's integrated scanner was VERY rudimentary. Patched it to resolve
some formatting issues and improve usability.
Fixes #4737, allowing the captain to open his office door from the comfort of his chair.

Makes the door control in the captain's office look for tagged doors instead of shutters.
Adjusts the pixel shift of the door control so the captain doesn't have to lean over his own desk to push it.
Makes the button require captain's access to use.
Fixes  #5532 and increases the time required for organs to become infected from wounds

Also removes the now unnecessary get_cure_threshold() proc, caps the
rate at which an organ can receive germs from wounds, and makes germs
spread from external to internal organs happen one organ at a time
instead of all at once.
Makes minor wounds harder to infect
Tweaks internal organ spread rate
Increases cough rate for lung infections
Health Analyzer can read all types of beneficial medicine
Merge pull request #5528 from PsiOmegaDelta/LazyCaptain

Fixes #4737 - Door control in captain's office now works
Fix: Painkillers stay in body for decent time
Fixes me being dumb with renaming variables
Mentors will no longer see highlighed names in ahelps / msay for players with special roles (Antags, etc.).
Fixes canmove updating wrongly on movable chairs
Removes duplicate defines, updates comments
Update PDA.dm

Patched the comment to match the actual, final behavior (Doh!)
Merge pull request #5539 from mwerezak/fix-5529

Fixes #5529
Merge pull request #5536 from Ccomp5950/mentor_no_highlight

Mentors will no longer see highlighed names in ahelps / msay for players with special roles (Antags, etc.).
Cleans code up for easier editing
Merge pull request #5537 from Hubblenaut/wheelchair

Fixes canmove updating wrongly on movable chairs
Cyborgs now understand all languages besides vox-pidgin
Fixes missing length check before pick()