Log Message:
Import byobu-5.69 as misc/byobu.

Byobu is a GPLv3 open source text-based window manager and terminal
multiplexer. It was originally designed to provide elegant enhancements
to the otherwise functional, plain, practical GNU Screen, for the
Ubuntu server distribution. Byobu now includes an enhanced profiles,
convenient keybindings, configuration utilities, and toggle-able
system status notifications for both the GNU Screen window manager
and the more modern Tmux terminal multiplexer, and works on most
Linux, BSD, and Mac distributions.