Annotate when we are in an OpenGL rendering zone.
Check for this in the VCL signal handler, and force OpenGL off here
if exception occurred inside an OpenGL code-path.

Reviewed-on: https://gerrit.libreoffice.org/17881Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>

Conflicts:
	vcl/source/opengl/OpenGLHelper.cxx

Change-Id: I85a4b3d4a374593dc55d01a39ec4c7c3c262c332
Reviewed-on: https://gerrit.libreoffice.org/17883Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>
Tested-by: Tor Lillqvist <tml@collabora.com>