Refactor command line parsing

I am trying to use Courier as part of a powershell script in Octopus Deploy, however their token-replacement does not work unless the token is surrounded by white space, which unfortunately breaks the argument parsing in Courier.
To get around this issue, I have replaced the argument parsing with a common library (https://commandline.codeplex.com/).  The existing commands still work, plus there are shorthand variations.