Functioning API filtering and more API docs.
Add djangorestframework to requirements.
Return systems as URLs from interfaces.
Fix docs conflict.
Make some related objects links and add label, domain fields.
Adjust API URLs to match Cyder UI URLs.
Clean up dynamic interface API serializer.
Protect user's API keys from other users, tidy up.
Merge branch 'test_django-rest-framework2' into api_keyvalues

Conflicts:
	cyder/api/authtoken/templates/authtoken/token_detail.html
	cyder/api/v1/api.py
	cyder/api/v1/routes.py
	docs/api/intro.html
	docs/api/intro.rst
Small API fixes and filtering working.