bnc#591147: OOXML import: Import video file too.

Change-Id: Ie9b6c5ff866269e5d7a26d025cb1c0d884ff1134
(cherry picked from commit b7006f3c2f8f71f4d4721c6e5cdc122628c756f0)
Reviewed-on: https://gerrit.libreoffice.org/11468
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>