Move low level logic to module code and versioning logic to versioning code.
Metas strip position was handled in diffrent way compared to other strips.
This was introduced in c8b0d25794 as bugfix for T28158.
I disagree with such design. Meta strips should be handled in same way as
any other strips.
I have tested this change and haven't found any problems.
No problems after checking T28158 as well.
There should be no functional changes on user level.
Reviewed By: campbellbarton
Differential Revision: https://developer.blender.org/D9972