sawdust mod

Sawdust to ground from cleaning delimb and cut of tree. When cut with chainsaw or woodharvester machine, this mod simulate the leavings and sawdust with default woodchips tipped to ground, that then need to be load or clean. When chainsaw in use or when woodharvester he grabbed tree, is possible to change "dust" level from 0 (off) to 3 (max), default 2. Please note that only in zone ok for tip to ground woodchips are generated.