- removed other flickr api library calls from authenticate
 - added placeholder py file for downloading photosets
 - updated comments and removed unused code
 - added filename/title update functionality
 - added photo set meta info updates
 - added validate functionality to check files from Flickr and database
 - added dry run to upload to see which directories will get uploaded
 - added separate create() in upload for when a new set is created
 - added bulk admin delete_selected so that it will delete from Flickr as well
 - added delete from Flickr support
 - overrides save() and delete() for Flickr synchronization