Added a new tool, CollectBaseDistributionByCycle, that computes the
nucleotide distribution per cycle.  Also fixing up MeanQualityByCycle,
since I copied code from there.
Merge pull request #23 from nh13/nh_collect_base_distribution_by_cycle

Added a new tool, CollectBaseDistributionByCycle, that computes the
Added % at 15X and 25X to the calculated metrics.
Merge pull request #41 from broadinstitute/tf_wgs_15x

Added % at 15X and 25X to the calculated metrics.
Release 1.119