regression: 'with pixels' affects 'all.dem'

[Hans-Bernhard B. <br...@ph...>]

As threatened, I've begun regression-testing prospective new
patches against the existing code.

And already found the first one: the current edition of the "with pixels &
friends" patch (after fixing a conflict in misc.c...) causes off-by-one
differences to the current head of CVS.  Affected plots include a
considerable subset of 'surface.dem' (starting at the first that has x**3
in it, then every plot up to the second plot of the sinc function), the
see-through sphere plot in world.dem, and all the pm3d "flush" option's
demos.

-- 
Hans-Bernhard Broeker (br...@ph...)
Even if all the snow were burnt, ashes would remain.