Update so that can be run in installed python examples directory (including import of the plplot_python_start.py module there which helps to find location of installed PLplot modules and extension modules).
Update so that can be run in installed python examples directory (including
import of the plplot_python_start.py module there which helps to find
location of installed PLplot modules and extension modules).

svn path=/trunk/; revision=4249

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