Add build system

Add autoconf style build infrastructure to the ZFS tree.  This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.

scripts/zfs.sh

@@ -0,0 +1,74 @@
+#!/bin/bash
+#
+# A simple script to simply the loading/unloading the ZFS module stack.
+
+basedir="$(dirname $0)"
+
+SCRIPT_COMMON=common.sh
+if [ -f "${basedir}/${SCRIPT_COMMON}" ]; then
+. "${basedir}/${SCRIPT_COMMON}"
+else
+echo "Missing helper script ${SCRIPT_COMMON}" && exit 1
+fi
+
+PROG=zfs.sh
+UNLOAD=
+
+usage() {
+cat << EOF
+USAGE:
+$0 [hvud] [module-options]
+
+DESCRIPTION:
+	Load/unload the ZFS module stack.
+
+OPTIONS:
+	-h      Show this message
+	-v      Verbose
+	-u      Unload modules
+	-d      Save debug log on unload
+
+MODULE-OPTIONS:
+	Must be of the from module="options", for example:
+
+$0 zfs="zfs_prefetch_disable=1"
+$0 zfs="zfs_prefetch_disable=1 zfs_mdcomp_disable=1"
+$0 spl="spl_debug_mask=0"
+
+EOF
+}
+
+while getopts 'hvud' OPTION; do
+	case $OPTION in
+	h)
+		usage
+		exit 1
+		;;
+	v)
+		VERBOSE=1
+		;;
+	u)
+		UNLOAD=1
+		;;
+	d)
+		DUMP_LOG=1
+		;;
+	?)
+		usage
+		exit
+		;;
+	esac
+done
+
+if [ $(id -u) != 0 ]; then
+	die "Must run as root"
+fi
+
+if [ ${UNLOAD} ]; then
+	unload_modules
+else
+	check_modules || die "${ERROR}"
+	load_modules "$@"
+fi
+
+exit 0