Minor syntax improvements. Fix Vagrant 'run vagrant init' warning.
Improve install message. Pre-prompt for password.
Set Docker host via docker-osx env command (available since 0.8.0).
Improve debug info message.
Minor changes to setting Docker OSX defaults and building with Fig.
Fix syntax errors. Oops..

Luckily we have the 'doos debug' command at our disposal!
Also remove the doos_parse_default_options function.