Make it easier to identify the installed Docker Toolbox version

Please make it easier to identify the version of Docker Toolbox installed, for better troubleshooting information.

  • Have docker, docker-compose, etc. show the Docker Toolbox version, when available.
  • Have Kitematic About show the Docker Toolbox version, when available.
  • Consider offering a docker-toolbox script, that supports -v | --version flags
  • Have a pkg entry for io.docker.pkg.dockertoolbox, not just the constituent packages