small performance improvement when intersection filter is enabled
added template parameter to some triangle intersectors to disable intersection filter
Merge branch 'v2.3' into devel
setting version to 2.3.1
Merge branch 'devel' of https://github.com/embree/embree into devel
disabled debug prints in bvh8i_builder
created specializations of chunk and hybrid kernels for triangle4 and triangle8, one with intersection filter enabled and one with intersection filter disabled