Blender Git Loki

Bumping version to 2.80

This should have been done earlier. But now that we may see more activity in master due to bcon3 merges, it is even more important to stress out the separation between master and 2.8.

Also I needed the version bump for idproperties doversion (they needed
to happen in _after_linking, and we don't have access to
DNA_struct_elem_find there).

Last but not least, every time I posted a video or image from 2.80, I
got someone confused about the version showing in the infobar.