FIX #449 js for changing templates
Run tests with Django 1.4.2, as newer django-mptt requires that
Codify req on django >= 1.4.2 for django-mptt requiring that
Merge branch 'master' into next

* master:
  Codify req on django >= 1.4.2 for django-mptt requiring that
  Run tests with Django 1.4.2, as newer django-mptt requires that
Merge branch 'fix-449-js-for-changing-templates' of git://github.com/bmihelac/feincms

* 'fix-449-js-for-changing-templates' of git://github.com/bmihelac/feincms:
  FIX #449 js for changing templates
Merge branch 'master' into next

* master:
  FIX #449 js for changing templates
Some weird images would trigger and exception that raised an exception in the exception handler, thus breaking the medialibrary admin interface.

ValueError actually has no strerror, so just stringify the whole exception and hope for the best.