Support XBPD

[janhohenheim]

Idk how much work this is, but in many places their API is fairly similar :)

[qhdwight]

Good idea, is on my list

[qhdwight]

Ok this is going to be a pain with cfg and feature selectors...

[janhohenheim]

Oh no! Which parts of the API are diverging enough to be a pain?

[qhdwight]

I just haven't worked with conditional compilation too much in Rust yet.

The branch xbpd has some initial testing but currently errors out in runtime.