distribute use of RouteAddedOrRemoved to appropriate places.

It might be wise to use this rather than GUIIdle but that needs further investigation

libs/ardour/session.cc

@@ -2191,6 +2191,8 @@ Session::new_midi_track (const ChanCount& input, const ChanCount& output, boost:
 
 			new_routes.push_back (track);
 			ret.push_back (track);
+
+			RouteAddedOrRemoved (true); /* EMIT SIGNAL */
 		}
 
 		catch (failed_constructor &err) {
@@ -2581,6 +2583,8 @@ Session::new_audio_route (int input_channels, int output_channels, RouteGroup* r
 
 			ret.push_back (bus);
 			
+			RouteAddedOrRemoved (true); /* EMIT SIGNAL */
+
 			ARDOUR::GUIIdle ();
 		}
 
@@ -2705,6 +2709,8 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
 			++control_id;
 
 			ret.push_back (route);
+
+			RouteAddedOrRemoved (true); /* EMIT SIGNAL */
 		}
 
 		catch (failed_constructor &err) {