Fix list typographical error that was preventing gcw.h and plplotcanvas.h from being distributed.
Fix list typographical error that was preventing gcw.h and plplotcanvas.h from
being distributed.

svn path=/trunk/; revision=6022

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