change default msg_throttle to 1
change default msg_throttle to 1

even for simple cases like plotting,
having more than one outstanding update seems like too much,
so let's give 1 a try.

cornhundred/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,SylvainCorlay/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,SylvainCorlay/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets