add update playback again until further notice

Former-commit-id: ef97c06cbc6b084d9b4dbcdfc2d05123132a6c0c

engine/api.py

@@ -154,6 +154,10 @@ from template.engine.api import callbacks
 
 _templateStartEngine = startEngine
 
+def updatePlayback():
+    #TODO: use template.sequencer.py internal updates instead    
+    cbox.Document.get_song().update_playback()
+
 def startEngine(nsmClient):
     _templateStartEngine(nsmClient)