In svn_export_empty_files.py, do not sacrifice GNU getopt behaviour everywhere, just because it is only available from Python 2.3 onwards.
In svn_export_empty_files.py, do not sacrifice GNU getopt behaviour everywhere,
just because it is only available from Python 2.3 onwards.

* contrib/client-side/svn_export_empty_files.py: Use gnu_getopt if available,
    fall back to standard getopt if not.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@855876 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion