makefile.am: Fix maintainer-clean target

Signed-off-by: Geoff Levand <geoff@infradead.org>
diff --git a/Makefile.am b/Makefile.am
index 6bd21a4..c7adeed 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,3 +1,5 @@
+ACLOCAL_AMFLAGS = -I m4
+
 AM_CFLAGS = @WARN_CFLAGS@ @ALTIVEC_CFLAGS@
 
 extra_dist_files = \
@@ -143,3 +145,9 @@
 twin_ttf_twin_ttf_LDADD = @FREETYPE_LIBS@ -lm
 twin_ttf_twin_ttf_CFLAGS = -g @WARN_CFLAGS@
 twin_ttf_twin_ttf_CPPFLAGS = @FREETYPE_CFLAGS@ -I$(top_srcdir)/twin_ttf
+
+MAINTAINERCLEANFILES = Makefile.in aclocal.m4 compile config.* configure \
+	depcomp install-sh ltmain.sh missing twin_def.h.in* $(PACKAGE)-*.gz
+
+maintainer-clean-local:
+	rm -rf m4
diff --git a/configure.ac b/configure.ac
index 7418e02..405a419 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,6 +25,7 @@
 
 AC_INIT([libtwin],[0.0.3],[Geoff Levand <geoff@infradead.org>])
 AC_CONFIG_AUX_DIR(.)
+AC_CONFIG_MACRO_DIRS([m4])
 AM_INIT_AUTOMAKE([subdir-objects])
 AM_MAINTAINER_MODE