Add full /etc/lsb-release parsing and improve Ubuntu detection
Add full /etc/lsb-release parsing and improve Ubuntu detection

    - Add grains lsb_distrib_{id,release,codename,description}
    - If /etc/lsb-release doesn't exist on an Ubuntu box, check
      if it is Ubuntu by reading /etc/issue.net
    - Set grains['os'] to 'Unknown Linux' on unknown distributions

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt