added ability to customize padding between tracks in image, changed position of tick labels in ruler
added ability to customize padding between tracks in image, changed position of tick labels in ruler

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