New Coop Entrance
Fix Coop progress sign

- Change to p1 model instead of brushes
- Fixed the orientation so it actually works
Exit room, and part of corridors
P1 style panels, and tbeam update

- P1 panels use piston arms to match the normal panel arms
- Tbeam has effects working correctly now.
Exit corridors

4 is fully done.
Fixed panel, corridor 2 done
Exit corridors done!

Now to release this!
Merge remote-tracking branch 'origin/P1-Coop'
Little bugfixes

- Ensure fizzlers play anims
- Try to ensure obs room is sealed
- Add toolsblack into fizzler model, to make it look nicer on white
walls
Add tsaddons-src/ to readme
Fix .gitignore
Fix .gitignore again
Merge remote-tracking branch 'origin/master' into dev