Add install_name (soname)

--- tclconfig/tcl.m4
+++ tclconfig/tcl.m4
@@ -1703,7 +1703,7 @@
 	    ])
 	    # TEA specific: link shlib with current and compatiblity version flags
 	    vers=`echo ${PACKAGE_VERSION} | sed -e 's/^\([[0-9]]\{1,5\}\)\(\(\.[[0-9]]\{1,3\}\)\{0,2\}\).*$/\1\2/p' -e d`
-	    SHLIB_LD="${SHLIB_LD} -current_version ${vers:-0} -compatibility_version ${vers:-0}"
+	    SHLIB_LD="${SHLIB_LD} -install_name \$(pkglibdir)/\$(PKG_LIB_FILE) -current_version ${vers:-0} -compatibility_version ${vers:-0}"
 	    SHLIB_SUFFIX=".dylib"
 	    # Don't use -prebind when building for Mac OS X 10.4 or later only:
 	    AS_IF([test "`echo "${MACOSX_DEPLOYMENT_TARGET}" | awk -F '10\\.' '{print int([$]2)}'`" -lt 4 -a \