Add omxDefaultComputePlan() test.
Add omxDefaultComputePlan() test.

jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx