Use a boot script instead of having autoreconf recurse

Use a boot script instead of having autoreconf recurse
It used to be the case that
    autoreconf
in the root would also autoreconf in any libraries that need it, and
    ./configure
in the root would also configure all the libraries.

However, cabal now configures the libraries, so they were getting
configured twice.

Thus now a small shellscript, boot, autoreconfs the root and all libraries
that need it, and ./configure in the root doesn't configure the libraries.