in `nbextensions/config/main`:  * support other config sections, as well as the default `notebook`
in `nbextensions/config/main`:
 * support other config sections, as well as the default `notebook`

juhasch/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,jbn/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,jbn/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,jbn/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,jbn/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions