Vagrantfile port forwarding usages documented. Added usage via envvar FORWARD_PORTS for custom port or list of comma-separated ports
Docker-DCO-1.1-Signed-off-by: Keyvan Fatehi <keyvanfatehi@gmail.com> (github: keyvanfatehi)
Merge pull request #3188 from keyvanfatehi/vagrant-port-forwarding-list

Vagrantfile port forwarding made more flexible (w/ comments)