Cleanup of vote view.
Cleanup of vote view.

 * Vote.objects.get_or_create to Vote.objects.create try/except. This
   will allow us to solve issue #42 in the future.
 * Change response mimetype to 'application/json'

mozilla/mozmoderator,mozilla/mozmoderator,johngian/mozmoderator,johngian/mozmoderator,mozilla/mozmoderator,johngian/mozmoderator,akatsoulas/mozmoderator,akatsoulas/mozmoderator,akatsoulas/mozmoderator,johngian/mozmoderator