The application exits in a sane way now, either by hiting the return key on the canvas or by closing the window.  A dialog window is popped up for confirmation.
The application exits in a sane way now, either by hiting the return
key on the canvas or by closing the window.  A dialog window is popped
up for confirmation.

svn path=/trunk/; revision=2680

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