Make notification sounds configurable

app/src/actions/settingsActions.js

@@ -43,6 +43,11 @@ export const toggleHiddenControls = () =>
 		type : 'TOGGLE_HIDDEN_CONTROLS'
 	});
 
+export const toggleNotificationSounds = () =>
+	({
+		type : 'TOGGLE_NOTIFICATION_SOUNDS'
+	});
+
 export const setLastN = (lastN) =>
 	({
 		type    : 'SET_LAST_N',