eqMassVolVis, new volume renderer example

usage example:

volVis -m ~/tmp/_bucky_64_raw/octree_file_0.dat -- --eq-config examples/eqMassVolVis/eq_configs/1-pipe_lab.eqc

the octree file can be generated from raw volume data by using the dataConverter tool.
use "dataConverter --help" for more information.