Updating generateIndelocatorPFResults.py to work with the current expected directory structure.

--misc other minor improvements to generateIndelocatorFPResults.py
Adding generateStrelkaFPResults.py, a slight modification of the indelocator version.
Work on GatherResults

--Adding exception handling for the case where vcftools doesn't output any files because there is nothing to compare.

--Adding printout to GatherResults.scala.