Readds the atmos venting tower
Adjusts the nuke op shuttle prison cell
Merge pull request #7248 from Baystation12/master

Master into dev.
Adds image for cult talismans

So they aren't blank when examined.
Fix num2hex()'s handling of zero
Merge pull request #7250 from GinjaNinja32/num2hex2

Fix num2hex()'s handling of zero
Readds the engine coolant replacement tvalve and splits the coolant loop into two pipenets again (allows for a pressure/temp difference).
Merge pull request #7249 from mwerezak/atmos-tower

Atmos tower, Nuke prison, talismans, engine
Fix for #7232.
Fix for #7204.
Merge pull request #7254 from Segrain/master

Bugfixes.
Merge branch 'master' of https://github.com/Baystation12/Baystation12 into dev