Emit Signal when plugin-stats change

libs/ardour/ardour/plugin_manager.h

@@ -116,6 +116,9 @@ public:
 	/** plugins were added to or removed from one of the PluginInfoLists */
 	PBD::Signal0<void> PluginListChanged;
 
+	/** Plugin Statistics (use-count, recently-used) changed */
+	PBD::Signal0<void> PluginStatsChanged;
+
 	/** A single plugin's Hidden/Favorite status changed */
 	PBD::Signal3<void, ARDOUR::PluginType, std::string, PluginStatusType> PluginStatusChanged; //PluginType t, string id, string tag
 

libs/ardour/plugin_manager.cc

@@ -1655,6 +1655,7 @@ PluginManager::stats_use_plugin (PluginInfoPtr const& pip)
 		statistics.erase (ps);
 		statistics.insert (ps);
 	}
+	PluginStatsChanged (); /* EMIT SIGNAL */
 	save_stats (); // XXX
 }