ATS - Grand Canyon Rebuild V1.3 (1.39.x)

Version 1.3 Changelog:
- Crashes in sector -0015+0001 (Around Montrose)

Version 1.2:
- Curb height bug which came with ATS 1.39
- Traffic not spawning around the rebuilded area
- Fixed various terrain gaps

Version 1.1:
Compatible with ATS version 1.37
Released a small bugfix

Grand Canyon Rebuild project is released

Authors: FisherJB