fdo#73436 Let SdXImpressDocument handle css.drawing.* requests directly

...instead of handing off to base class, so that potential wrapping in SdXShape
(in create) is not skipped.

Change-Id: I57fb10ef478688a5a0c1c3c736efbd55a7172423
Handle osl_createThread failure

Change-Id: I58144461d3941359f8ea6c2bd547486b2c8ae81a
SalDisplay::Dispatch shall apparently return bool

Change-Id: I46ab0ef04b598a4154659f9a1e1cbb2164023b63