[3.7] bpo-4630: Add cursor no-blink option for IDLE (GH-16960) by miss-islington · Pull Request #17142 · python/cpython

@ZackerySpytz @miss-islington

This immediately toggles shell, editor, and output windows, but does not affect other input widgets.
(cherry picked from commit 9c28449)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

terryjreedy