Add a page that illustrates how to change fonts using the new plsfont command.
Add a page that illustrates how to change fonts using the new plsfont command.

svn path=/trunk/; revision=8282

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