Re: moving from contrib to bin

Here is a rebase of my previous patch set.  I have integrated the
various minor fixes from Michael and Andres.  I have dropped moving
pg_standby, because no one seemed to like that.

I wasn't able to do anything with Michael's Mkvcbuild.pm patch, since
that appeared to include a significant refactoring along with the actual
move.  Maybe the refactoring can be done separately first?

Otherwise, I suggest we start with the first patch, pg_archivecleanup,
fix up the Windows build system for it, and commit it, and repeat.