Changed plfill to call plP_plfclp rather than plP_fill directly.  Fixes problems with fills not being clipped.
Changed plfill to call plP_plfclp rather than plP_fill directly.  Fixes
problems with fills not being clipped.

svn path=/trunk/; revision=2652

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