Joux Plane for Assetto Corsa update

Finally got around to fix the issues in Joux Plane with the recent Assetto Corsa early access versions causing collision problems in some parts of the track. There were some leftover triangles under the track in a few places from lower LOD level mesh used originally by RBR.

A few other improvements are included also, changelog for version 1.3:

Removed some remnants of low detail geometry under the track causing collision issues with newer AC versions

Broken track section no longer adds dirt to tyres

All grass is now valid track to avoid penalty from small cuts

Added more zoomed in external cameras