Blender Git Loki

Refactor: Ensure there's always a valid file editor tool region

So far the file browser code had some lazy creation for the tool region,
even though it should always be there. The only reason I can see for
this is compatiblity. So I simply added versioning code to add the
region in case it's not there. Now we should be able to savely assume
the tool region to be there, whithout any unusual lazy-creation.