Allow recordings to be 'unlisted'

Unlisted is a state between published and unpublished. They are still
published in the server, but will not appear to anyone other than the
user that created the recording.
It is done using a metadata attribute and required several changes in how
the application handles publishing and unpublishing.

app/assets/javascripts/landing.js

@@ -100,7 +100,8 @@
         .tooltip('fixTitle');
     });
 
-    $('.center-panel-wrapper').on ('click', '.meeting-invite', function (event) {
+    // button used to send invitations to the meeting (i.e. "mailto:" link)
+    $('.center-panel-wrapper').on('click', '.meeting-invite', function (event) {
       var meetingURL = Meeting.getInstance().getURL();
       var subject = $(this).data("invite-subject");
       var body = $(this).data("invite-body").replace("&&URL&&", meetingURL);