LP#882586: In Serial Control View, show copy templates owned by ancestors

When creating/editing distributions, dropdowns for Receive Unit Template
and Bind Unit Template now show copy templates owned not only at the
distribution's holding lib, but at any of the holding lib's ancestors.

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Signed-off-by: Dan Wells <dbw2@calvin.edu>