New genotype and somaticgenotype to store more intermediate statistics

- Added new CalledGenotype and CalledSomaticGenotype (and Kryo serializers) to save more intermediate variant calling information used for filtering

This also makes a distinctions between germline and somatic calls to the filters can be applied appropriately.  Part of breaking down #147 and is dependent on #162 
I don't think there is, I just have an instinct to make these sequences of filter object `apply` calls / reassignments to the `var` into one chain of function calls. Not necessary/actionable here though, sorry for the confusion