firepony: Reduce batch size, add progress indicator
firepony: Reduce batch size, add progress indicator

Lower the batch size to cope with larger SNP databases (the batch size
remains hard-coded for now).

Add a progress indicator (output one dot for each processed batch).

NVlabs/firepony,broadinstitute/firepony,NVlabs/firepony,broadinstitute/firepony,NVlabs/firepony,NVlabs/firepony,broadinstitute/firepony,broadinstitute/firepony