barcharts.py: add more control over auto sizing
barcharts.py: add more control over auto sizing

kanarelo/reportlab,Distrotech/reportlab,kanarelo/reportlab,kanarelo/reportlab,kanarelo/reportlab,kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,Distrotech/reportlab,Distrotech/reportlab