Hard coded relationship URI in sd/source/,
sw/source/filter and oox/source/export/ directory has been replaced with
method calls.

Change-Id: Ie1b9542325fa4143bddea2582aa5e946094e457d
Reviewed-on: https://gerrit.libreoffice.org/37433Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>