Deal with the various Django versions:

- User cannot select the wanted version presently.
- This poses a problem with some extensions and may likely for a while,
  as Django 1.7 among others created it's own migrations, obsoleting
  South, without being compatible with it.
- Write a default-versions and USES solution, based upon code in
  Uses/python.mk.
- Also fix too strict package requirements in setup.py and chase
  upstream to 3.10
Merge branch 'ports-mrs' of github.com:melvyn-sopacua/freebsd-ports into ports-mrs

Sync