Brett and I eating Burritos from Little Chihuahua at my house.

Plan is for Brett to work on Clip-it-Good (the Chrome Extension)'s
camli support (currently non-existent), and get it to:

   -- select an image
   -- upload the image blob
   -- create the permanode blob
   -- create (and sign, with the signing server) the "become" claim,
      pointing the permanode at the image
   -- create (a signed) "tag" blob, tagging an image e.g. "funny"

I will work on docs & signing server tests & signing verification
endpoint.