Fix xhr content-types.

Express.js expects a Content-Type to know how to parse the body.
By default jQuery send application/x-www-form-urlencoded transforming boolean
values into strings. So for instance false becomes "false".
When the payload comes back via the eventsource channel, testing the boolean
value will systematically succeed.

The fix adds the proper json content type (i.e. application/json) and encodes
the data vie JSON.stringify.
Merge pull request #35 from tOkeshu/fix-xhr-content-type

Fix xhr content-types.
Check the origin when receiving a stopcall event
Merge pull request #36 from tOkeshu/fix-stopcall

Check the origin when receiving a stopcall event on the mobile page
Merge pull request #34 from fqueze/detach-chat

Close the floating chat window when detaching a call to a tab (when our ...
Fix logout.
Merge pull request #39 from tOkeshu/fix-logout

Fix logout.
Increase the ping time to 20s
Remove the channelPing function
Merge pull request #40 from tOkeshu/higher-ping-time

Increase the ping time to 20s
Merge pull request #41 from fqueze/mute-local-video

Mute local videos to avoid the huge local echo we have since gum is call...
Do not set the audio+video stream to the audio element.