flickr: set primary photo as camliContentImage on album

Change-Id: I3e805e3e64878d7f0057957c0be476a1a613cb21
Merge "flickr: set primary photo as camliContentImage on album"
picasa: set url property on photos and albums

Change-Id: If89ee61138e4fb80e68f87130c5fe189b7d82582
Merge branch 'master' of https://camlistore.googlesource.com/camlistore