We've gotten enough questions that are related to building systems rather

We've gotten enough questions that are related to building systems rather
than anything about busybox that I'm deeming it a FAQ, and answering it.

I gave a quick swipe to a couple of other slightly stale questions along
the way.  The busybox 1.01 README has much more detailed versions of these
answers, that should probably be propogated to the 1.1 line and perhaps bits
of it transplanted to the FAQ?  (Or just have the README visible on the
web page someplace?)