write abs_top_srcdir to and abs_top_buildir to the Makefiles (older

automake versions didn't do this automatically)

[[Imported from SVN: r5819]]

m4/dune_all.m4

@@ -44,6 +44,8 @@ dnl do not use LT_INIT since we want to be compatible with libtool 1.5
 
   AC_SUBST(ACLOCAL_AMFLAGS, "$ACLOCAL_AMFLAGS")
 
+  AC_SUBST([abs_top_srcdir])
+  AC_SUBST([abs_top_builddir])
   AC_SUBST(am_dir, $DUNE_COMMON_ROOT/am)
 ])