Blender Git Loki

Object API changes so these functions now require a scene as first argument:
create_mesh, create_dupli_list, make_display_list and is_visible.

This is done in order to make these context independent as the RNA API should
be as much as possible, and to fix #21297 and #21719, where there was an
assumption from these functions that there is a scene in the context, which
does not work for external render engines exporting in a separate thread.

Also avoided using context in a number of other functions, ideally only UI/WM
type functions should use context.

I've updated the scripts in trunk, but the addons and external ones in
development will need updates too.