gtltcube run is too long.

[barrettp]

It takes gtltcube >4 hours to process 15 years of Fermi data (~2 GB), while all other processes take <1 minute each. It therefore take days to process 20 or more targets. This process needs much improvement.

[kerrm]

You are probably making a full-sky livetime cube for each target, but you usually only need to make one.