What:	Byzi 0.2
Where:	https://github.com/aryler/Byzi
Who:	Stuart Cassoff <stwo@users.sourceforge.net>
When:	Spring 2017

Confine pointer and keyboard events to a window sub-tree.

The Byzi extension for Tk provides a simple means to
block keyboard, button and pointer events from Tk widgets, while
overriding the widget's cursor with a configurable busy cursor.

The Byzi extension is based on the Tk 8.6.6 busy command sources.