Initialize the __pl structure x/y min/max values, as __pl_store assumes it!
Initialize the __pl structure x/y min/max values, as __pl_store assumes it!

svn path=/trunk/; revision=4691

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