Add omxMatrixLeadingLagging missing from previous commit
Add omxMatrixLeadingLagging missing from previous commit

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