What was found to not work is something like "-ro services.rdb" referencing an
XML-format services.rdb that itself contains relative uri attributes.  The uno
executable would not make an absolute file URL from "services.rdb" due to no
leading ".", so trying to absolutize any relative uri attributes against the
relative .rdb URL lead to MalformedUriExceptions.

Change-Id: Ib41fc8e42b9848f5e77f44c86e1857a3d287d634