Add ray-casting based query for point lying inside/outside mesh

[Shane-J-Latham]

Would be good for the API to support multiple mesh objects in one scene, i.e. return inside/outside result for each mesh object in a scene.

[odf]

Agreed! That's already possible with the combination of EmbreeScene and TriangleMesh, but in that case the scene object does not retain the raw mesh data. For EmbreeSceneExtended, it should be fairly easy to maintain a list or dictionary of meshes stored in the instance and then in intersections() use ray_hit.hit.geomID to pick the correct one.