Cut over nightly benchmarks to LongField/IntField.

[rmuir]

benchUtil.py still refers to the old field names (e.g. dayOfYearNumericDV):

          elif sort == '<int: "dayOfYearNumericDV">':
            task.sort = 'DayOfYear'

I'm not sure what it is doing, looks like parsing toString() of sorts? I just did the grep to look for any missed stuff.

[rmuir]

also the toString() might look very different than just changing the fieldname because now we use a different sort (multi-valued one), I'm not sure.

[jpountz]

Thanks @rmuir I fixed this, it now works at least when running a benchmark locally.