Import BWA 0.7.5a, apply previous changes made in Seal for BWA 0.5.x and resolve conflicts.
Update data structures specification in bwa_core.py so that they match BWA 0.7.5a.
Merge pull request #3 from okulev/port-bwa-0.7

merge hackathon work on updating  Seal Seqal to  bwa-0.7