faster shutdown when in a conference

mitchcapper/FSClient/Conference.cs

@@ -321,7 +321,7 @@ namespace FSClient {
 				menu.Items.Add(UserMenu(user));
 		}
 
-		private void EndConference() {
+		public void EndConference() {
 			ConferenceAction("kick all");
 		}
 

mitchcapper/FSClient/MainWindow.xaml.cs

@@ -617,6 +617,10 @@ namespace FSClient {
 		private void Window_Closing(object sender, CancelEventArgs e) {
 			try {
 				Windows.systray_icon_remove();
+				Conference.instance.EndConference();
+				foreach (var call in Call.calls)
+					if (!call.call_ended)
+						call.hangup();
 				broker.Dispose();
 			}
 			catch { }