Update of /cvsroot/pdl/PDL/Graphics/PLplot
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv13324/Graphics/PLplot
Re-implemented the plshades interface, which now accepts subroutine pointer
arguments "defined" and "pltr". The "z" pdl matrix is column-dominant, as
is usual with the other functions.
The high-level function shadeplot, which uses plshades, is changed
accordingly, as well as the test t/plplot.t.