shapes.py: add overprint properties to group and don't ever initialize
shapes.py: add overprint properties to group and don't ever initialize

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