Merge pull request #18 from fqueze/master

Handle multiple instances of the same user logged in at the same time.
Merge pull request #19 from fqueze/master

Support making audio-only calls
Merge pull request #20 from fqueze/master

Fix Persona authentication in a sidebar that's reloaded after being hidden
Add the xpi and an update.rdf to the website. This works as the website supplies https connections
Change the index page to give details on installing the add-on.
Merge pull request #21 from fqueze/master

Audio-only calls no longer require hacking the SDP offer
Merge pull request #22 from Standard8/xpi

Add an add-on that automatically sets up the social api and preferences for the demo
Avoid flickering of the 'Sign in' button.