Changed DEFAULT_FAR_CLIP to TREE_SCALE
Removed magic number to use DEFAULT_NEAR/FAR_CLIP
Made zFightingAdjust a ratio to the distance (currently 4%)
Merge branch 'master' of https://github.com/highfidelity/hifi into editVoxels_zFighting

Conflicts:
	examples/editVoxels.js
Merge pull request #3213 from Atlante45/editVoxels_zFighting

Edit voxels z fighting