The triangle-ray intersection function used a hard coded epsilon,
which did not work for triangle meshes, that were either too small
or too large. Newly the epsilon may be provided to the AABBTreeIndirect
search functions externally and IndexedMesh calculates a suitable
epsilon on demand from an average triangle mesh edge length.
enumerate is unusual and would only work effectively with random access iterators
this for_each takes advantage of tbb blocked_range
replace ccr_::enumerate with flexible for_each
enumerate is unusual and would only work effectively with random access iterators
this for_each takes advantage of tbb blocked_range
