listdlg.m: return Octave value rather than Java int object.(bug #41931). Make parameter list case-insensitive. Return empty matrix rather than empty cell list on failure. * listdlg.m: Use for loop to index into java array to get octave value. Use strcmpi to parse input options. Correctly return an empty matrix rather than empty list if dialog fails.

#include <octave/oct.h>

DEFUN_DLD (helloworld, args, nargout,
           "Hello World Help String")
{
  int nargin = args.length ();

  octave_stdout << "Hello World has "
                << nargin << " input arguments and "
                << nargout << " output arguments.\n";

  return octave_value_list ();
}