Changed course files to JSON format

All course loading/unloading from files is now done in the JSON format.
Merge branch 'master' of https://github.com/dreadmullet/JC2-MP-Racing

Conflicts:
	CourseManifest.txt
	server/sCourse.lua
	server/sCourseCheckpoint.lua
Fixed up spacing before dreadmullet complains.