py api:

ray cast function, very useful to be able to cast rays into the scene for scripts.

  hit_co, hit_no, success = scene.ray_cast(start_co, end_co)


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55957 954f8c5b-7b00-dc11-b283-0030488c597c