Blender Git Loki

Bake from multires mesh
=======================

Added option to baked named "Bake From Multires" which is avaliable for
normals baking and displacement baking.

If this option is enabled, then no additional hi-res meshes and render
structures would be created . This saves plenty of memory and meshes
with millions of faces could be successfully baked in few minutes.

Baking happens from highest level against viewport subdivision level,
so workflow is following:
- Set viewport level to level at which texture would be applied
during final rendering.
- Choose Displacement/Normals baking.
- Enable "Bake From Multires" option.
- You're ready to bake.

Displacement baker had aditional option named "Low Resolution Mesh".
This option is used to set if you want texture for realtime (games)
usage.

Internally it does the following:
- If it's disabled, displacement is calculated from subdivided
viewport level, so texture looks "smooth" (it's how default
baked works).
- If it's enabled, dispalcement is calculated against unsubdivided
viewport levels. This leads to "scales". This isn;t useful for
offline renders much, but very useful for creating game textures.

Special thanks to Morten Mikkelsen (aka sparky) for all mathematics
and other work he've done fr this patch!