was still using opengl volume renderer, not ospray
now the smart volume mapper test no longer hangs
plug memory leaks and style issues
deletes for every new in the volume renderer
remove dead code (including the disabled temporal cache)
vtk style, alphabetize lists, this->, 80 chars, CapsIvars, etc

flesh out the ospray standalone volume mapper

only the standalone mapper gives the z buffer to ospray. then
the volume terminates before the surfaces start. later it alpha blends
the results onto the color buffer.
the internal ospray volume mapper doesn't need to do anything special
since ospray already has the depths from the surfaces it rendered.
wip because this is slow and hacked together and the opengl linking
changed but we are not actually using it yet.

adjust test to work with GL1 too