* Renamed BKE_pbvh_raycast_project_ray_root to
BKE_pbvh_clip_ray_ortho for greater
clarity.
* BKE_pbvh_clip_ray_ortho no longer strictly clips
within the input ray interval. This is not necassary
for orthographic views and was too prone to floating
point error. The function is only called to clip
brush rays for orthographic views so this is acceptable.