Make mxTryHard() less likely to throw an error for difficult jobs.
Make mxTryHard() less likely to throw an error for difficult jobs.

It's possible for mxRun() to return a "solution" where the fitfunction
has value NaN, especially if the start values are non-feasible.

JuKa87/OpenMx,JuKa87/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,JuKa87/OpenMx,jpritikin/OpenMx,JuKa87/OpenMx,mhunter1/OpenMx,JuKa87/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,JuKa87/OpenMx