Blender Git Loki

Refactor 'fit in camera view' code, and expose it to RNA.

This changes BKE's fitting code to use `BKE_camera_params_compute_viewplane` instead of
`BKE_camera_view_frame`. This allows that code to work with orthographic projection too.

Also, two funcs were added to rna's Object, to resp. get the projection matrix of that
object (mostly useful for cameras and lamps objects), and return position this object
should be to see all (to fit) a given set of points.

Reviewers: campbellbarton

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D961