Implement symbol versioning


diff --git a/aclocal.m4 b/aclocal.m4
index ffe58e3..e851e14 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1343,6 +1343,7 @@
 m4_include([m4/ax_pthread.m4])
 m4_include([m4/cxx_have_std_libs.m4])
 m4_include([m4/framework.m4])
+m4_include([m4/ld-version-script.m4])
 m4_include([m4/libtool.m4])
 m4_include([m4/ltoptions.m4])
 m4_include([m4/ltsugar.m4])