Sextractor is slow at NERSC

[suchyta1]

It takes a lot longer to run sextractor at NERSC than BNL. I think this is something about how sextractor opens the files, I don't think it keeps everything in memory, because it doesn't seem to consume an amount of memory as large as our images. If that's true, it'll be doing more I/O, which is what's the bottleneck at NERSC.

I put this in the issues, because it's worth considering at least having an option to kill most of the band's nosim runs, because that could save considerable run time. In principle you could want these, but no one has really used them yet.