Updated cliffside from b7 to b7_2. The changes include:

- Fixed HDR lighting, leaving it as LDR lighting

Updated cliffside from b6 to b7. The changes include:

- Improved lighting
- Added an additional small healthkit on the top left path
- Fixed a bomb stuck exploit by the cliff pit at red spawn
- Fixed the sticky tank's crit noise not being played
- Added the regen tank from Nox
- Added the AltAttributes feature from Nox

Updated mvm_cliffside_b5 to mvm_cliffside_b6. The major changes include:

- Fixed an issue where players with invulnerability could survive the cliff death.
- Fixed an issue where engineers could build at the bottom of the cliff.
- Improved the transition between the skybox and the playable area.
- Overall performance should be better thanks to better optimization.
- Minor graphical improvements.

Added mvm_cliffside_b5