autoscroll
==========

Description
-----------
Optionally set the output autoscroll threshold, and/or add a selector to the toolbar to set it, and/or add a toolbar button to enable/disable it

Parameters
----------

* autoscroll_set_on_load
  Set an autoscroll threshold on notebook load. If false, the default is unchanged.
* autoscroll_starting_threshold
  Autoscroll threshold which would be set on notebook load. -1 disables autoscrolling.
* autoscroll_show_selector
  Add a selector to the toolbar to change the autoscroll threshold
* autoscroll_show_button
  Add a button to the toolbar to disable/enable autoscrolling
