XclObjComment formally cloned the SdrCaptionObj for a single
reason - to suppress functionality of the UNO API implementation
in SvxShape::GetBitmap - non-inserted SdrObjects did not create
Graphic return values.

Changed this to use an exclusive flag at SdrCaptionObj, only
accessible for XclObjComment. Due to bad/undefined behaviour
of SdrObjects that are not iinserted anywhere (see old comment
in XclObjComment) there is no way to return to cloning the
SdrObjects just to have them without being added to a SdrPage.

Also improved the time eater UNO API implementation SvxShape::GetBitmap
to use more modern stuff to create the Graphics needed. All the
time constructing a full E3DView and setting SdrObjects selected
and getting the selection as graphic is way too expensive. That
way save may even get somewhat faster.

Last was to cleanup the bInserted flag in SdrObject. It is no
longer needed, being inserted now depends on being a member
of an SdrObjList (Group or Page) - sounds normal anyways and
is a synergy effect of already done AW080 cleanups.

Checked now on linux. Problem is UnitTest 'testN777345' which
checks file "n777345.docx".

First point is that this only happens
  #if !defined(MACOSX)
  #if !defined(_WIN32)
so it's clear why I detected no problem on Windows.

Second point is that this test takes a checksum of a Graphic
that is created using getReplacementGraphic() this value *will*
change - of course - every time creation of that graphic is
even *slightly* modified, so from my POV this UnitTest is
defined to fill quite often. It may even create different
results on different systems (!). Adaption of the test value
 will be needed quite often and makes this test questionable.

Change-Id: If0918831a9cbd61b31298aeac7342e1913ee6c7a
Reviewed-on: https://gerrit.libreoffice.org/57758
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>