remove widget/kernel coupling code
remove widget/kernel coupling code

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