templates/*:
- make the sub-heading titles consistent...mainly left alignment and a few name changes
models.py:
- override clean method for Site and Subject models to throw a validation error if duplicates are attempted within a project
views.py:
- changed the saving of form data to use the ModelForm save method. Not sure why or how it was working with saving the Model object directly without getting it out of the form, but that is definitely undocumented behaviour which will probably cause some bad times sooner or later.
api.py:
- new SiteResource for the Site model
- enabled filtering to list all samples or subjects for a site or project

urls.py:
- registered SiteResource to our API
- changed api_name to 'repo'