Added section on Debian packages.  I am keeping in our web site an apt-getable area for the PLplot Debian packages.   These area is only for the stable Debian distribution.
Added section on Debian packages.  I am keeping in our web site an
apt-getable area for the PLplot Debian packages.   These area is only
for the stable Debian distribution.

svn path=/www/trunk/; revision=7488

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