Argument parsing/handling

[eviefp]

The code for parsing/handling arguments is a bit old and clunky. I think I mentioned optlicative as an option. Do you think the library is ready? If not, can we open up an issue there and figure out what's missing?

cc @Thimoteus

[hdgarrood]

👍 As I see it, its age isn't really the problem: more the fact that pretty much everything is stringly-typed and there are unsafe casts littered everywhere.