changed mapping percentage calculation per alignment length bin to use non-N sequence length like the total mapping percentage per chromosome
changed mapping percentage calculation per alignment length bin to use non-N sequence length like the total mapping percentage per chromosome

Ensembl/ensembl,danstaines/ensembl,willmclaren/ensembl,mjg17/ensembl,muffato/ensembl,at7/ensembl,muffato/ensembl,mjg17/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl,danstaines/ensembl,james-monkeyshines/ensembl,willmclaren/ensembl,muffato/ensembl,at7/ensembl,mjg17/ensembl,mjg17/ensembl,at7/ensembl,james-monkeyshines/ensembl,muffato/ensembl,Ensembl/ensembl,Ensembl/ensembl,danstaines/ensembl,at7/ensembl,james-monkeyshines/ensembl