The migration of org.broadinstitute.variant into the Picard repo is
complete. This commit deletes the org.broadinstitute.variant sources
from our repo and replaces it with a jar built from a checkout of the
latest Picard-public svn revision.
-Moved some of the more specialized / complex VariantContext and VCF utility
methods back to the GATK.
-Due to this re-shuffling, was able to return things like the Pair class back
to the GATK as well.