Address the speed of plotting large hggroup groups and in particular contours (bug #31305). Changes to address this include - Use __go_patch__ in __contour__ rather than patch so that the cost of setting up the callback functions is avoided. The contourgroup callback handles the updating of properties. - Add children_property class to store children in a list so that adding and deleting children is a low cost operation. - Create a new version of update_axis_limits code that doesn't force the recalculation of all of the objects children. Patch also allows unclosed patch contours with the FLTK backend.

#!/bin/sh
#
# Like mv $1 $2, but if the files are the same, just delete $1.
# Status is 0 if $2 is changed, 1 otherwise.

if test -r $2; then
  if cmp $1 $2 > /dev/null; then
    echo $2 is unchanged
    rm -f $1
  else
    mv -f $1 $2
  fi
else
  mv -f $1 $2
fi