Update vendor to 2c89fe7
Update django-reversion to 1.5.1

Newer versions of pip complain about django-reversion==1.5 for some
reason.
Update settings to work with new debug toolbar
Remove unused form and view

When Django is imported, the Django debug toolbar must modify the root
urlconf (via debug_toolbar.models.patch_root_urlconf), which requires
it to import the module containing the form definition.

'manage.py syncdb' imports Django, which imports the form definition,
but the form definition does a query on the 'range' table, causing
syncdb to fail if there's not already a 'range' table.

The form isn't used anymore, so the easiest thing to do was to
remove it.