add accessor for id of individual; reformat code a little; add a draft of a get_pedigree_string function.
add accessor for id of individual; reformat code a little; add a draft of a get_pedigree_string function.

solgenomics/sgn,solgenomics/sgn,solgenomics/sgn,solgenomics/sgn,solgenomics/sgn,solgenomics/sgn,solgenomics/sgn