Description: Set automake option subdir-object to remain forward compatible.
Author: Bas Couwenberg <sebastic@xs4all.nl>
--- a/src/operation/overlay/Makefile.am
+++ b/src/operation/overlay/Makefile.am
@@ -1,6 +1,9 @@
 #
 # This file is part of project GEOS (http://trac.osgeo.org/geos/) 
 #
+
+AUTOMAKE_OPTIONS = subdir-objects
+
 SUBDIRS = 
 
 noinst_LTLIBRARIES = libopoverlay.la
--- a/src/planargraph/Makefile.am
+++ b/src/planargraph/Makefile.am
@@ -1,6 +1,9 @@
 #
 # This file is part of project GEOS (http://trac.osgeo.org/geos/) 
 #
+
+AUTOMAKE_OPTIONS = subdir-objects
+
 SUBDIRS = 
 
 noinst_LTLIBRARIES = libplanargraph.la
--- a/tests/unit/Makefile.am
+++ b/tests/unit/Makefile.am
@@ -1,6 +1,9 @@
 #
 # This file is part of project GEOS (http://trac.osgeo.org/geos/) 
 #
+
+AUTOMAKE_OPTIONS = subdir-objects
+
 INCLUDES = -I$(top_srcdir)/include -I$(top_srcdir)/tests/unit/tut -I$(top_builddir)/capi
 
 TESTS = geos_unit
--- a/tests/xmltester/Makefile.am
+++ b/tests/xmltester/Makefile.am
@@ -5,6 +5,8 @@
 #top_srcdir=@top_srcdir@
 #top_builddir=@top_builddir@
 
+AUTOMAKE_OPTIONS = subdir-objects
+
 TESTS = testrunner
 
 CLEANFILES = testrunner 
