Final commit before major changes to SAM.py package. Going to overhaul it and make performing multiple SAM file analyses in one reading of a SAM file possible. Also adding in coverage_count, which calls upon SAM.py to output the mean and range of coverage values for Sue1, Col, Bur, Tsu, C24, and Ler. Also added sxn_gene_variation.py which looks at the per-gene variation across 312 SxN F2s to observe whether or not DupHMM's list of duplicated genes demonstrates more variation than what is seen in a random selection of genes