Now can work with either TK or Tcl-DP.  Changed to use TK by default.
Now can work with either TK or Tcl-DP.  Changed to use TK by default.

svn path=/trunk/; revision=1271

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