This is work in progress, mainly uploaded to show it's being worked on. There
are TODO comments in the code explaining what remains to be done.
This change removes about 3000 lines of code, and means sculpting tools and
drawing code only have to work with Mesh and BMesh types. This includes the
new tools in the sculpt branch, which should work on multires combined with
The downside is increased memory usage (TODO: measure) and maybe slower
switching between levels and in and out of sculpt mode. Fast Navigate is also
no longer available after this, hopefully drawing the low poly mesh for
navigation is no longer as important with our improving drawing code.