"keepStreamsOpened" and "localStreams" added.

// if you want to keep streams opened even if session is closed.
connection.connection.keepStreamsOpened = true;

connection.onSessionClosed = function() {
var stream = connection.localStreams[streamid];
};

Though it isn't needed, however there is "stopMediaStream" method as
well:

connection.stopMediaStream(MediaStream);

"stopMediaStream" will simply invoked "stop" method over
MediaStreamTrack (if available), otherwise it'll fallback to
"MediaStream.stop" method. It'll also invoke "stream.onended" event
which has no support in Firefox yet.

Removed: connection.caniuse.checkIfScreenSharingFlagEnabled. It was
redundant.