in `nbextensions/config`:  * improve extension ui show/hide and scrolling behaviour
in `nbextensions/config`:
 * improve extension ui show/hide and scrolling behaviour

original-commit-id: 29d4ebbb97e461e313aba385228b2595e4d35366
original-commit-url: https://github.com/ipython-contrib/IPython-notebook-extensions/commit/29d4ebbb97e461e313aba385228b2595e4d35366

jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator