Picard genotype concordance

A new command is available as of Picard 1.122 to compare two VCF files for the purpose of genotype concordance.

This PR includes the gmt wrapper with tests to run GenotypeConcordance using Picard 1.123.  @iferguson90 is currently working on the packaging of the latest version of PIcard.

This PR also contains a new RefAlign command intended to replace CompareSnpsSummary for new models that use mpileup.  Currently those CompareSnp results are all zeros since it doesn't handle the new file format.  The new command is entirely VCF based.
As for using get_or_create all the time, I was worried about run time performance.  I also experienced some locking issues when running many of these at one time during testing.  I recall seeing pretty long run times when I originally created the results.  This would be less a concern if the results were generated during SomVal