Management script to fix some of Torfaen changes.
Merge branch 'issues/134-torfaen'
Refactor some parameter handling.

Now raise an error if a bad generation parameter is provided. For
consistency, add the min_generation parameter to /children and /point.
Fixes for Django 1.7.

Also make sure all tests run in Django < 1.6, and with a
non-4326 SRID setting.