Finally had time to figure out the problem "caused" by django_compressor,
so we can no re-enable it. Fixes #3

There has been issues when running a full test suite (for pinry and
the entire Django stack), and test fixtures are hard to maintain anyway,
so rewrite tests to use a Model mocker library (Factory Boy) to populate
database.

Generate thumbnail and standard image on request, and use
http://github.com/mirumee/django-images for generating them. Also,
remove the CreatePin page as pin creation is going to be done
in JavaScript. Create UploadImage view for uploading images from
computer.

-e should be used only with repositories apparently

The previous commit uses url syntax from Django 1.5, which is incompatible with earlier versions. Bump the Django version
and use the stable/1.5.x git branch until it's officially released.