Minimal port of xfbuild to D2

[SiegeLord]

I have recently done a minimal port of the xfbuild utility
(minimal in the sense that it still uses Tango) to D2. I am aware
that Andrej Mitrovic has also done a port of it to D2, but I was
scared off by it's alpha status. My port should, in principle,
have no new bugs over the original (it seems to work just as well
as the original in my limited tests). You can find the repository
here:

https://github.com/SiegeLord/xfbuild

-SiegeLord