Add defaults method like request.defaults

[gsf]

The defaults method in the request library is useful for creating a new request function​ with some options already set. It can also take a requester function, which is a lightweight way to extend functionality. The requester is undocumented but is at this point not much code to implement and could be an interesting refactor for xhr.

[naugtur]

@jmeas Apart from opinions which are always welcome, would you mind sharing if this form of extending xhr fulfills your needs (the ones originally leading to your PR with qs) ?

[jamesplease]

I think it would fulfill my needs, @naugtur . If we added this, we could revert the other API, with the added benefit of being more consistent with request.

[naugtur]

My point exactly.
If you guys want to PR this I won't get in your way.
Let me know.
I'll be able to dig in after Easter if you don't want.

BTW. I'm looking for someone to share npm publishing access too.

[jamesplease]

@naugtur , I've got it on my to do list to dig more into this library. I'm going to work on those integration tests first, I think. Time permitting, I'd be happy to help out with more, too.

[gsf]

I may have time this week to implement but I can't make that promise. If you get to it first, @naugtur, I'd be happy to review.