known short options are accepted when passed as long options

[amagura]

If -x is a known short option, bebopt, in its current form, will accept --x. I don't think that very many people use Bebopt, which is perfectly understandable, seeing that Bebopt is such a young library and hardly production ready, all the same, I'm in no rush to fix this bug. I don't really write programs in JavaScript very much, since other languages are far more suitable for writing applications than JS, so unless somebody else would like to use Bebopt more and would like me to fix it, or has already fixed it for me 😉, I might be obliged to do something about it.