feat(mail): filter mailbox by flagged messages

Fixes #1417

UI/WebServerResources/js/Mailer/Mailbox.service.js

@@ -342,17 +342,6 @@
     return angular.isDefined(this.$selectedMessage);
   };
 
-  /**
-   * @function toggleUnseenOnly
-   * @memberof Mailbox.prototype
-   * @desc Toggle filter by unseen messages only. Requires a round trip to the server.
-   */
-  Mailbox.prototype.toggleUnseenOnly = function() {
-    var _this = this;
-    this.$unseenOnly = !this.$unseenOnly;
-    this.$filter(Mailbox.$query);
-  };
-
   /**
    * @function $filter
    * @memberof Mailbox.prototype
@@ -408,6 +397,9 @@
     if (this.$unseenOnly)
       options.unseenOnly = 1;
 
+    if (this.$flaggedOnly)
+      options.flaggedOnly = 1;
+
     // Restart the refresh timer, if needed
     if (!Mailbox.$virtualMode) {
       var refreshViewCheck = Mailbox.$Preferences.defaults.SOGoRefreshViewCheck;