ChangeD - the D changelog generator script

Per Walter's request.
Written in D, powered by std.net.curl.

Caveats: we still have a very awkward situation with linking to libcurl on POSIX. 
Basically it requries a manual linking step with gcc and few lines worth of command line. Would that be a high time to anyhow fix it so that dmd passes libcurl at the right place in the command line by itself?

See:
http://d.puremagic.com/issues/show_bug.cgi?id=7044