Changed the fallback code to use the result form the realize() call, removed the code path from running a PBuffer as a seperate graphics context (this was found to be slower than running single threaded so its not worth the extra complexity).
Changed the fallback code to use the result form the realize() call, removed
the code path from running a PBuffer as a seperate graphics context (this
was found to be slower than running single threaded so its not worth the
extra complexity).


git-svn-id: 23b6355f2bb369032457de4eb5f713ee134f73a8@4577 16af8721-9629-0410-8352-f15c8da7e697

joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg