Add support for nonces

[cajus]

Services like dex require a nonce for token auth. Added it.

[antonelepfl]

@cajus I think you can use something like:

let client = new JSO({
  client_id: ...,
  authorization: ...,
  request: {'nonce': "<YOUR PARAM>'},
});

I have a server that requires this nonce and I'm passing it like that and it works
Is that what you need?

[cajus]

Dex adds a nonce, but it doesn't work without the patch.