add --disable-cpplibs configure option (SF#1723295: https://sourceforge.net/tracker/index.php?func=detail&aid=1723295&group_id=13478&atid=313478

test/Makefile.am

@@ -15,13 +15,17 @@
 #  restrictive of those mentioned above.  See the file COPYING.Xiph in this
 #  distribution.
 
+if FLaC__WITH_CPPLIBS
+CPPLIBS_TESTS = test_libFLAC++.sh
+endif
+
 TESTS_ENVIRONMENT = FLAC__TEST_LEVEL=@FLAC__TEST_LEVEL@ FLAC__TEST_WITH_VALRGIND=@FLAC__TEST_WITH_VALGRIND@
 
 SUBDIRS = cuesheets flac-to-flac-metadata-test-files metaflac-test-files pictures
 
 TESTS = \
 	./test_libFLAC.sh \
-	./test_libFLAC++.sh \
+	$(CPPLIBS_TESTS) \
 	./test_grabbag.sh \
 	./test_flac.sh \
 	./test_metaflac.sh \
@@ -35,7 +39,7 @@ EXTRA_DIST = \
 	metaflac.flac.ok \
 	picture.ok \
 	test_libFLAC.sh \
-	test_libFLAC++.sh \
+	$(CPPLIBS_TESTS) \
 	test_flac.sh \
 	test_metaflac.sh \
 	test_grabbag.sh \