draft solution -- for review only -- do not merge!

@haf while this is not valid Ruby (which I do not master), this will hopefully allow you to get the ideas of the proposed solution. Your comments are appreciated. 
I´ll need to dig into this as the command line looks good. I assume, you´re on OSX.

The error message relates to the argument parsing step with the commandline tool wrapper, i.e. before the call to the FSharp.Formatting library call was done.