Textured roofs and shrunk skybox in a few places to support another addon.

Fixed Rebel base area being too small.

Changed a few window textures to something more uniform.
Removed a door in the basement of the house next to Rebel base area.

Fixed a few more broken aspects.

Adjusted skybox size to ease package delivery.
Moved Combine city-scanner spawn location to middle of map.

Added navmesh and AI nodes.