flickr: set primary photo as camliContentImage on album

Change-Id: I3e805e3e64878d7f0057957c0be476a1a613cb21
Merge "flickr: set primary photo as camliContentImage on album"
website/camweb: redirect to right scheme on www. request

Fixes http://camlistore.org/459

Change-Id: Icf69e404a6985c984688c291e88da365721ee029
importers: add SupportsIncremental accessor

If an importer is efficient at running regularly, it returns true.

If it's not true, the UI won't allow turning on automatic runs.

Flickr doesn't set it (yet).
corpus: respect more attributes when looking up permanode's time

Change-Id: I2ed9f9f100109510c1617e465a8d3e2b3261d244
picasa: set url property on photos and albums

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