The former method of creating a symlink for lena.pgm in the install directory worked except for the case where DESTDIR was specified.  Work around this problem by using a copy of lena.pgm rather than a symlink.
The former method of creating a symlink for lena.pgm in the install
directory worked except for the case where DESTDIR was specified.  Work
around this problem by using a copy of lena.pgm rather than a symlink.

svn path=/trunk/; revision=7196

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