Newer versions of autoconf don't come with automake and aclocal bundled, so use the equivalent commands from autoconf: autoreconf instead.  Info from this article:  http://www.gnu.org/software/automake/manual/html_node/Upgrading.html
Merge pull request #164 from mdayaram/master

Updating autogen.sh script.
Merge https://github.com/hcatlin/libsass