Added the PLStream pointer to the widget structure, to allow faster access to PLplot internals.  Added "cmd" widget commands "scmap0", "gcmap0", "scmap1", "gcmap1" for setting/getting palette settings.
Added the PLStream pointer to the widget structure, to allow faster access
to PLplot internals.  Added "cmd" widget commands "scmap0", "gcmap0",
"scmap1", "gcmap1" for setting/getting palette settings.

svn path=/trunk/; revision=816

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot