Blender Git Loki

ID.make_local(): handled mont29's feedback

- returning 'self' or 'self->newid'
- rewording RNA descriptions

Removed some unused code.

Moved bpy.data.make_local(?) to bpy.types.ID.make_local(?)

Added bpy.data.make_local() that can make a single ID block local.

Note that this will not work reliably when the idblock is referenced
from a library. It is the caller's responsibility to ensure a proper
state. Use with care.