Make it work again with the current version of BrowserID

On advice of Sean McArthur:
* Changed WebView's URL.
* Changed API function called when the page loads.
Make user's email address available to caller

Extract email address from assertion,
and store it in controller's .emailAddress property.
Code cleanup and header-doc comments.
Oops, converted tabs to spaces
Merge pull request #1 from couchbaselabs/master

Fixes & improvements