added option to flip which is reference genome
added option to flip which is reference genome

asherkhb/coge,LyonsLab/coge,LyonsLab/coge,LyonsLab/coge,asherkhb/coge,asherkhb/coge,asherkhb/coge,asherkhb/coge,LyonsLab/coge,asherkhb/coge,asherkhb/coge,LyonsLab/coge,LyonsLab/coge,asherkhb/coge,LyonsLab/coge,asherkhb/coge,LyonsLab/coge,LyonsLab/coge