Modified Casava18ReadNameEncoder to correctly display filter status.  Previously it was treated as "passing filter" when in fact Illumina's intended meaning in the read name is "is filtered" (i.e. does *not* pass filter).  The enum for the field has also been renamed to more accurately reflect its content.
Merge pull request #42 from broadinstitute/kt_fix_quality_score_encoding

Add harmonization of differing Quality Score Encoding schemes in the SAN...