"egrep -o" isn't portable and not available on OpenBSD, for example. So
let's use sed instead to get the automake version. The expression used
now is less specific but should work as well ...
[ -z "$AUTOMAKE" ] && Notfound automake
[ -z "$AUTOCONF" ] && Notfound autoconf
-AM_VERSION=`$AUTOMAKE --version|head -n 1|egrep -o "([1-9]\.[0-9]+(\.[0-9]+)*)"`
+AM_VERSION=`$AUTOMAKE --version | head -n 1 | sed -e 's/.* //g'`
ifs=$IFS; IFS="."; set $AM_VERSION; IFS=$ifs
AM_MAJOR="$1"; AM_MINOR="$2"; AM_PATCHLEVEL="$3"
echo "Detected automake $AM_VERSION ..."