RC4

Changes to both Underground and Underworld:
* Updated nav, including fixed bomb drop locations - bomb will not be getting stuck on top of rocks anymore
* Tanks now explode after they successfully release the bomb
* Updated nobuild entities on rocks at the front of the map
* Added nobuild to the area under the walkway next to the mineshaft, as sentry busters cannot go into this area.
* The top of the central mine entrance next to the upgrade station is more walkable
* Fixed a couple displacements where you could get stuck
* Enabled radial fog on env_fog_controller and sky_camera entities
* Changed Render Mode to Color on func_respawnroomvisualizer entities
* The front upgrade station no longer fails to open when swapping missions mid-mission
* Added a glass window to the bomb hatch
* Moved func_respawnroom and func_respawnroomvisualizer closer to the main bot gate; Moved the caution tape underneath the gate
* It is no longer possible to achieve victory in a wave after a tank has deployed the bomb
* Fixed the scale of the func_respawnroomvisualizer texture for red spawn (only visible in spectator)
* Light blocker to reduce lighting on props at the front of the map
* Compiled with staticproplighting. Certain props have this disabled as a stylistic choice (example being the rocks at the front of the map)
Changes to Underworld:
* Removed Mothership sound from the skull

Release Candidate 3:
Added doors to grinder pit for during boss waves