Bring the introductory paragraphs more up to date with my understanding of the present build situation. Geoffrey, I noticed your instructions for the alternative where you have to modify python have not been updated since 1996 so I had to put in a warning about that.  By all means remove the warning if those instructions still work fine.
Bring the introductory paragraphs more up to date with my understanding of
the present build situation. Geoffrey, I noticed your instructions for the
alternative where you have to modify python have not been updated since 1996
so I had to put in a warning about that.  By all means remove the warning
if those instructions still work fine.

svn path=/trunk/; revision=3471

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