Run pythondemos.py rather than individual xw??.py examples which no longer work standalone.
Run pythondemos.py rather than individual xw??.py examples which no longer
work standalone.

svn path=/trunk/; revision=3285

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