Makes tabs and windows think they're visible even when they're not.
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greatest.deepsurf.us/scripts/456228/1309113/Absolute%20Visibility.js
Based on https://addons.mozilla.org/en-US/firefox/addon/always-visible/ and turned into a library that can be used on other UserScripts to disable visible state changes in websites.