Changed some old constructs "plfunc()" into calls to xml entities "&plfunc;".
Changed some old constructs "plfunc()" into calls to xml entities "&plfunc;".

svn path=/trunk/; revision=5613

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