RFC: A new approach to OsStr support

[EliteTK]

I would like to preface this by saying that I am happy to just create a fork of getargs with my ideas and leave this project be.

I have prepared a set of patches of progressive improvements which culminate in the addition of &OsStr as Argument support.

I think more tests would be useful to have etc. But this was mainly a proof of concept for myself.

Additionally the patch set adds the feature of not negative numbers as options taken from argparse in python. This is optional.

Really, I am mostly interested in comments and feedback from others who have worked on this project as I think they may be best suited to evaluate the commits.

I am curious as to what I could have done better and if this could ever be merged.

Edit: It's also worth mentioning that this change does introduce some minor (10%-50%) performance regressions. For me this is acceptable given the performance is still above and beyond anything which I would ever be concerned by. But I would be curious to know if this can be improved on.