would have liked to make the AcquireWriteAccess methods DLLPRIVATE, but
they are needed by the workbench and testing code

Change-Id: I22497788eb68dfb84b7e542e5ef53322892a5274
Reviewed-on: https://gerrit.libreoffice.org/51310Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Jenkins <ci@libreoffice.org>