 * Really big update
 * Add support for Firefox Klar, Firefox Focus, Firefox Lite and Fenix
 * Download and install the app inside FFUpdater (thanks wolfgang42 for the groundwork)
 * Improve UI
 * Verify the certificate of the downloaded and installed app
 * Many improvements
 * Thanks DeenHyper74 and xin for translations
 * Remove Fennec Beta and Fennec Nightly because their are not developed anymore https://bugzilla.mozilla.org/show_bug.cgi?id=1627518