Controls need not to be rendered when they are
visible as Windows (they then render themselves).
Also added some needed cleanups for better display
of control primitive decomposition as Bitmap.
Change-Id: I976cd791f9f080a7ab567232303d5d4f0b6dff05
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/178725
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@me.com>
Armin Le Grand (Collabora)
f3f70ef02f