This basically reverts b6b1ded0, since it
introduces tdf#118707, and I cannot reproduce any of the original problems
when reverting.
The patch itself is technically correct, but the problem is in the Windows
implementation of clipboard handling, which uses delayed processing
of setting clipboard contents. This leads to previous clipboard contents
being deleted too late, and with shared_ptr instances of SdrCaptionObj may
get deleted after the related SdrModel has already been deleted.
A proper fix would be to remove the stupid delayed processing from
the clipboard code, but that's non-trivial. If that gets fixed, the change
removing ScCaptionPtr may most probably be applied again.

Change-Id: I29634847486aa955b20483c9eb38bba4fed87187
Reviewed-on: https://gerrit.libreoffice.org/67725
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>