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 
Sure - shouldn't be any interplay between them.  The former represents germline variants and the later somatic (two sample) variants.  

Don't believe they would be used together, other than perhaps to see if they overlap etc.  Separate files works for me.