[spec] Make autotools fix less hack-ish

Turns out even upstream automake admits that the checkout
timestamps are an issue with all the rebuilding. This doesn't
really make it any better, but we can fix is without creating
the "hack" directory and the aclocal-1.13 symlink.

From http://www.gnu.org/software/automake/manual/html_node/CVS.html:

"Maintainers interested in keeping their package buildable from a CVS
 checkout even for those users that lack maintainer-specific tools might
 want to provide an helper script (or to enhance their existing
 bootstrap script) to fix the timestamps after a cvs update or a git
 checkout, to prevent spurious rebuilds."