The autoconf/automake guys want AC_INIT to be passed the details of the
package directly rather than going through AM_INIT_AUTOMAKE. Update them
both to use the newer style.
This also allows us to pass in contact details for the project.
We set the minimum autoconf version to 2.64 as that's the first one to
support passing the homepage URL in to AC_INIT. That's a pretty old
release by now, so it shouldn't be a problem.