Split LLgen off to be self-contained, and not necessarily part of the ACK. Replaced its build system with one based on pm. Rewrote the README. Updated the license text to match the overriding license common to all the ACK.

util/LLgen/bootstrap.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+# $Id$
+#
+# Script to rebuild LLgen's own parser with LLgen.
+
+set -e
+
+if ! (which LLgen > /dev/null); then
+	echo "You can only bootstrap the LLgen parser if you've already got"
+	echo "LLgen installed."
+fi
+
+(cd src && LLgen -vvv -x tokens.g LLgen.g)
+
+echo ""
+echo "You should now be able to rebuild LLgen with the new parser."