Fixed stepladder (was previously incorrectly using a prop_physics entity, when it should have been using prop_static)

Minor lighting tweaks

Music will now resume playing after loading a save

Change 11:
- Overall of first pool room, extra detailing added
- Slight detailing improvement in other rooms

This change has now been correctly applied. I previously uploaded an empty folder for change 11, change 12 rectifies that oversight

- Overall of first pool room, extra detailing added
- Slight detailing improvement in other rooms

- Minor tweaks to compile process to improve lighting

Fixed issue with campaign files, selecting the NPC free version from the menu will now load the correct map

- Added correct, updated VMF files
- Added menu options. Maps should now appear in the workshop addons section under the new UI

- Retired "potato PC" maps
- Removed some of the god rays less important to visuals to increase performance
- Fixed accidental placement of nodraw texture on one of the pillars in the largest room
- Statues in the final room are now rotated correctly
- Added monster clips to prevent alien controllers from disappearing down tunnels in the penultimate room

Further optimisations to lighting, fixes for AI on alien controllers (should no longer enter the water, or follow the wrong AI paths)