Fix up mxGenerateData corner cases
Fix up mxGenerateData corner cases

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