Map Fixes!

Fixes issue #3902
Computer Update Proc Fix

Fixes issue #2486
Resolves atmos computers not updating, adds an update proc to printing.
Implant mode changability, explosive variable fix

Fixed and upgraded as per Ravensdale's request in #3966
Girder health/laserkill fix

Allows girders to be broken by repeated laser shots to stop abuse against laserfire. Also, for actually being able to lase through walls if they're open.

Resolves issue #3796
Holostools/Stool Replacement

Fixes issue #3323
Adds in a holostool item, replaces all holodeck stools.
Updated changelog.html

Swag changelog update.
Merge pull request #3968 from Nanai/dev-freeze

Map Fixes V: Son of Areas