Variant factories now support multi-allelic variants, assigning proper indexes depending on which one is the 'main' alternate. #17
Variant stats classes vastly simplified: some deprecated classes deleted, others see attributes removed. #17 . Closes #14
Variant stats tested for biallelic variants
VariantStats class simplified a bit more, and some unit tests added for multi-allelic variants. #17
Some methods made public
Merge branch 'feature/multi-allelic' into develop