v4.0.0 - fragment based counting

• alleleCounter now counts per-fragment rather than per-read when overlaps occur.
  1. When members of a pair overlap and calls match the depth and allele seen are only counted once.
  2. When mate reads disagree on the call, the depth is counted as 2 and both allele counts incremented.
• Reworked perl to wrap C alleleCounter and just handle the extra format changes.
• Removed dependency on Bio::DB::HTS.
• Update to HTSlib 1.7
• Merged #43, providing 10X processing mode.