[Bf-codereview] Derivative filtering for multires baker (issue 13778045)

[sergey.vfx at gmail.com]

Reviewers: bf-codereview_blender.org,

Description:
This is an updated version of patch from
https://codereview.appspot.com/4837062

Changes comparing to old version:

- Applies on current trunk
- Style cleanup
- Derivative maps baking now possible with both multires and regular
bakers

Naming and descriptions in UI could be improved.
Reporting of scale is currently disabled. Not sure how to do reporting
best when baking multiple objects. Easiest way would be to report
several RPT_INFO. Other ideas are welcome.

Please review this at https://codereview.appspot.com/13778045/

Affected files (+264, -25 lines):
   release/scripts/startup/bl_ui/properties_render.py
   source/blender/editors/object/object_bake.c
   source/blender/makesdna/DNA_scene_types.h
   source/blender/makesrna/intern/rna_scene.c
   source/blender/render/extern/include/RE_multires_bake.h
   source/blender/render/extern/include/RE_shader_ext.h
   source/blender/render/intern/source/bake.c
   source/blender/render/intern/source/multires_bake.c