Add Testing.Options

As suggested in clean-test#4 (closed), this adds the command line options parser to Platform.

It does still throw an error if it sees options that it does not understand. Since there is no use case at the moment I didn't want to make this too complicated. It is possible to support custom options in a derivative application by filtering the list yourself first, or using --option. I feel that instead of solving this problem here we should rather have a general module to handle command line options if we want to fix this properly.