Added a quick fix so that hitting a carriage return when prompted for a filename no longer aborts the program.  Contributed by Mark Olesen.
Added a quick fix so that hitting a carriage return when prompted for
a filename no longer aborts the program.  Contributed by Mark Olesen.

svn path=/trunk/; revision=1182

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