Improve BLAT filter, require pysam 0.7.5
- Require pysam version 0.7.5 to stick with code using qpos
- Changed BLAT filter to use both the e-value and the identity scores. A read is valid if it has the highest of either of the scores.
- Changed mpileup filter to re-classify germline mutations without a high enough alternative allele percentage as possibly somatic.