Whitecliff rc4a

- Added 3d skybox
- Detailed the cliff face
- Added extra pickups around the map
- Fixed a problem where bots trampled on the grass

Spoiler: Screenshots

- Added gatebot support missing from a1
- Adjusted bot routes to compensate for the gate
- Adjusted bots within the provided pop file to be gatebots
- Fixed cobblestone fences slightly levitating off the floor
- Attached the magnets so a sign by the portcullis was not floating away