hol_light: fix script, upgrade to r189

This also tweaks the version number to just use the SVN revision (rather
than date), since it's unambiguous and increasing anyway.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
(cherry picked from commit 0f1f2115e91edb65ad3b4edea08ffeb96665a5c1)