Use BSD raw mode on darwin. Fixes nano, tmux and others

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Merge pull request #4648 from creack/fix_raw_mode_darwin

Use BSD raw mode on darwin. Fixes nano, tmux and others
add a breakathon for testing

Docker-DCO-1.1-Signed-off-by: Charlie Lewis <charliel@lab41.org> (github: cglewis)
Merge pull request #4649 from cglewis/release_add_breakathon

Add a "breakathon" for a testing/QA period to the release checklist