Add symlinks for tarball-dir version substitution

Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com>

diff --git a/foo-2.8/hello-debhelper_2.8.orig-foo.tar.gz b/foo-2.8/hello-debhelper_2.8.orig-foo.tar.gz
new file mode 120000 (symlink)
index 0000000..7eb21f2
--- /dev/null
+++ b/foo-2.8/hello-debhelper_2.8.orig-foo.tar.gz
@@ -0,0 +1 @@
+../dsc-3.0-additional-tarballs/hello-debhelper_2.8.orig-foo.tar.gz
\ No newline at end of file

diff --git a/foo-2.8/hello-debhelper_2.8.orig.tar.gz b/foo-2.8/hello-debhelper_2.8.orig.tar.gz
new file mode 120000 (symlink)
index 0000000..f0509a5
--- /dev/null
+++ b/foo-2.8/hello-debhelper_2.8.orig.tar.gz
@@ -0,0 +1 @@
+../dsc-3.0-additional-tarballs/hello-debhelper_2.8.orig.tar.gz
\ No newline at end of file