Overhaul use of __pltopt__.m to correctly check for cellstr, not just cell. * scripts/plot/private/__pltopt__.m: Use modern coding conventions. Eliminate unneeded input checking in subfunctions. Remove unused variables. * scripts/plot/contourf.m, scripts/plot/feather.m, scripts/plot/plotmatrix.m, scripts/plot/private/__bar__.m, scripts/plot/private/__quiver__.m, scripts/plot/private/__scatter__.m, scripts/plot/private/__stem__.m, scripts/plot/stairs.m: Use iscellstr, not iscell, to properly validate inputs to __pltopt__.

#!/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