Started work on LumiverseColor

Due to the use of vectors and matrices in many color calcs, the
header-only Eigen library was added for convenience.
Added ArnoldPatch class for Simulation and LumiverseVector class
Merge with new lib
Modified CMakeLists and added ArnoldWindowDriver class

Building with Arnold is now an CMake option. Currently the config is only available for Apple. ArnoldWindowDriver uses SDL 1.2 due to 2.0's problem with CMake. ArnoldWindowDriver is untested.