added authConfig to docker build
refactor and fix tests
when sharing a /var/lib/docker dir with more than one distribution, an existing lxc-start-unconfined softlink may point to a non-existant path, following that link (as Stat does) will cause the daemon to fail to start
install vbox guest additions if not latest
Merge pull request #3099 from vieux/fix_pull_build

added authConfig to docker build
Merge pull request #3219 from unclejack/vagrant_fix_version_check

install vbox guest additions if the latest aren't already installed
Allow untag operations with no container validation
Merge pull request #3217 from SvenDowideit/deal-with-changing-paths-for-lxc-start

lxc-start-unconfined softlink can go bad
Merge pull request #3230 from crosbymichael/allow-untag

Allow untag operations with no container validation