bugfix for issue 21 - multiple PG lines
bugfix for issue 21 - multiple PG lines

nlhepler/pysam,TyberiusPrime/pysam,pysam-developers/pysam,bioinformed/pysam,carolinux/pysam,TyberiusPrime/pysam,bioinformed/pysam,kyleabeauchamp/pysam,daler/pysam,mattions/pysam,kyleabeauchamp/pysam,TyberiusPrime/pysam,nlhepler/pysam,carolinux/pysam,daler/pysam,nlhepler/pysam,brendanofallon/pysam,brendanofallon/pysam,daler/pysam,daler/pysam,bioinformed/pysam,brendanofallon/pysam,mattions/pysam,mattions/pysam,mattions/pysam,dannon/pysam,carolinux/pysam,pysam-developers/pysam,TyberiusPrime/pysam,carolinux/pysam,brendanofallon/pysam,dannon/pysam,dannon/pysam,nlhepler/pysam,TyberiusPrime/pysam,pysam-developers/pysam,bioinformed/pysam,dannon/pysam,bioinformed/pysam,pysam-developers/pysam,carolinux/pysam,nlhepler/pysam,kyleabeauchamp/pysam,kyleabeauchamp/pysam,daler/pysam,mattions/pysam,brendanofallon/pysam,kyleabeauchamp/pysam,dannon/pysam