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.

module/Makefile.in

@@ -0,0 +1,54 @@
+subdir-m += avl
+subdir-m += nvpair
+subdir-m += unicode
+subdir-m += zcommon
+subdir-m += zfs
+
+modules:
+	# Make the exported SPL symbols available to these modules.
+	cp @SPL_OBJ@/@SPL_SYMBOLS@ .
+	$(MAKE) -C @LINUX_OBJ@ SUBDIRS=`pwd` @KERNELMAKE_PARAMS@ $@
+
+clean:
+	$(MAKE) -C @LINUX_OBJ@ SUBDIRS=`pwd` @KERNELMAKE_PARAMS@ $@
+	if [ -f @SPL_SYMBOLS@ ]; then $(RM) @SPL_SYMBOLS@; fi
+	if [ -f @LINUX_SYMBOLS@ ]; then $(RM) @LINUX_SYMBOLS@; fi
+	if [ -f Module.markers ]; then $(RM) Module.markers; fi
+
+modules_install:
+	# Install the kernel modules
+	$(MAKE) -C @LINUX_OBJ@ SUBDIRS=`pwd` \
+		INSTALL_MOD_PATH=$(DESTDIR) \
+		INSTALL_MOD_DIR=addon/zfs $@
+	find ${DESTDIR}/lib/modules/ -name 'modules.*' | xargs ${RM}
+	sysmap=${DESTDIR}/boot/System.map-@LINUX_VERSION@; \
+	if [ -f $$sysmap ]; then \
+		depmod -ae -F $$sysmap @LINUX_VERSION@; \
+	fi
+	# Install the required headers in to the kernel source
+	destname=zfs-@ZFS_META_VERSION@/@LINUX_VERSION@; \
+	instdest=$(DESTDIR)/usr/src/$$destname; \
+	(find . -mindepth 3 -name '*.h' | xargs -Ihdr sh -c \
+	 "DEST=hdr && install -D hdr $$instdest/\$${DEST#*/*/*/}") || exit 1
+
+modules_uninstall:
+	# Uninstall the kernel modules
+	$(RM) -R ${DESTDIR}/lib/modules/@LINUX_VERSION@/addon/zfs
+	# Uninstall the required headers from the kernel source
+	destname=zfs-@ZFS_META_VERSION@/@LINUX_VERSION@; \
+	instdest=$(DESTDIR)/usr/src/$$destname; \
+	$(RM) -R $$instdest
+
+distdir:
+	distfiles=`find . -name '*.c' -o -name '*.h'`; \
+	for distfile in $$distfiles; do \
+		distpath=`dirname $$distdir/$$distfile`; \
+		(/bin/mkdir -p $$distpath && \
+		 /bin/cp $$distfile $$distdir/$$distfile) || exit 1; \
+	done
+
+distclean maintainer-clean: clean
+install: modules_install
+uninstall: modules_uninstall
+all: modules
+check: