Replace mod_python with Django/WSGI

[Morten Brekkevold]

All the native mod_python tools of NAV have been converted to Django, which means NAV should now be servable as a WSGI app and no longer be dependent on mod_python.

mod_python development stopped quite a while ago, and although considered mature, it ties NAV to Apache, which is an irrational restriction.

The mod_python dependent parts of NAV should be refactored so that NAV can at least be served using mod_wsgi instead. However, authorizing access to arbitrary web server resources can still only be done using mod_python, so NAV should provide an alternative for users who still want to do this.

[Morten Brekkevold (mbrekkevold)]

fixes merged here: https://nav.uninett.no/hg/default/rev/da1d29a641b1