Kill deprecated code from initial Observer design

r+ by Lloyd, sitting right next to me
use browserid-verify library

fixes #89
added firefox-accounts support meta tag; ws cleanup
Merge pull request #90 from mozilla/browserid-verify

use browserid-verify library
Fix sending of the JSON response

Since we're sending a proper JSON response, jQuery automatically parses
it into it's data, rather than us having to do it ourselves.