Fixed an issue where a certain event was not triggering properly, causing trev to be visible at an unintended time

- Fixed an issue where a physics prop was getting stuck on an areaportal blocking brush during a scripted sequence in the canteen
- Added some stackable crates to the digsite for the vertically challenged

- Removed some console debug messages that were unintentionally left in one of the scripts

Thanks to Seven for pointing out these issues.

- Fixed a poorly sealed displacement
- Made a couple of jumps slightly easier
- Fixed a bug causing the fire doors not to open after a certain event

- Fixed a number of missing materials and sounds