Also simplify parent/child relationships, get rid
of double data (SdrPage/Parent infos in SdrObjects,
also in SdrObjList). This is all not needed - when a
SdrObject is inserted to a SdrPage, get SdrPage by
traveling over parents (no double info, member as soon
as inserted, ...).
More cleanups/reworks included, will need some more
cleanups, too.

Stabilizing: SetRectsDirty/DefaultStyleSheet

Had to correct the SetRectsDirty stuff for 3D due to
going down the hierarchy while the 2D implementation
goes the other direction -> endless loops. Added special
handling for 3D stuff for now (will be chnaged again when
SnapRect is no longer needed at SdrObject level).
Also had to adapt how the DefaultStyleSheet is set at
incarnated SdrObjects - better: their properties. Since
we now always have a SdrModel, it is possible to correctly
initialize with the correct default StyleSheet from that
SdrModel.
This needs to be done after ForceDefaultAttributes and in a
way that again deletes Items that are set in the StyleSheet.
This leads to an error in CppunitTest_sd_import_tests where
I checked tdf100491 - it is okay and thus I change the control
instance of the imported, XML-dumped file.
The less hard attributes, the better for Styles in general.

Cleanup of comments for last two commits

Corrected SvxShape::getParent()

Needed to get the direct parent, so test for SdrObject
first (to get SdrObjGroup/E3DScene), for SdrPage second

Fixed CppunitTest_sc_subsequent_export_test

Several problems arose. The used SdrCaptionObj was
Cloned, but the clone not inserted to a SdrPage. This
leads to not being able to access a UNO API imlementation
of the SdrPage (SvxPage) on lower levels.
It worked before due to SdrObject having a SdrPage*
additionally to being added to a SdrPage - this is exactly
the main cleanup this change does.
Looked for why it is cloned, could see no reasons. The
SdrCaptionObj exists during all im/export, not difference
to other SdrObjects (that do not get cloned). It is not
changed in any way. It *might* be to suppress a crash that
happened due to UNO API Service emfio/emfio not being
available in the UnitTest scenario. Interestingly it
did not crash with the cloned SdrCaptionObj, but the
Graphic exported was probably wrong.
Fixed by no longer Cloning the SdrCaptionObj and adding
emfio/emfio UNO API Service.

d139f821a5b39535a3e7b9c6261df7e18f8ae8ac
910e7f4bc628a715fda7545dffaf3369d5e76ea0
ca1de01b723051e09ac37d7ec7bba978beea41c5
3a76da1471dfe75e69847f64a6a3519ad21c8c9c

Change-Id: I986586e326b563acebf00d931a7084c6eb09e5f8
Reviewed-on: https://gerrit.libreoffice.org/54689Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>