__contour__.m: Overhaul function. * scripts/plot/private/__contour__.m: Redo input validation and parsing. Check for X and Y matrix inputs. Change level calculation to match contourc. Remove deprecated 'edgecolor' contour group property. Remove unused code. Use strcmp, not unnecessary strcmpi, on values returned from get().

#!/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