Speedtree perf lockdown
 - Automatically try to set the tree LODs (unification)
 - Make sure all Speedtrees are labelled Speedtree
 - Disable Smooth LOD transitions (perf test)
 - Set Alpha Cutoff properly
 - Switch shader to defaults (invert this when we're ready)
 - Limit billboard texture size to 1024, disable mipmapping
 - Force tree networking global (fixes pop in on some trees)
 - Force tree layer to Trees
 - Inverted TreeMesh placeholder behaviour