maint: Remove unnecessary whitespace at end of lines. * libgui/Makefile.am, libgui/graphics/Canvas.cc, libgui/graphics/EditControl.cc, libgui/graphics/Figure.cc, libgui/graphics/MouseModeActionGroup.cc, libgui/graphics/annotation-dialog.cc, libgui/graphics/annotation-dialog.h, libgui/graphics/gl-select.cc, libgui/graphics/module.mk, libgui/kb-layouts/default.keytab, libgui/kb-layouts/linux.keytab, libgui/kb-layouts/vt420pc.keytab, libgui/src/m-editor/find-dialog.cc, libgui/src/main-window.cc, libgui/src/octave-qt-link.cc, libgui/src/octave-qt-link.h, libgui/src/shortcut-manager.h, libinterp/corefcn/error.cc, libinterp/corefcn/find.cc, libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h, libinterp/corefcn/octave-link.cc, libinterp/corefcn/quadcc.cc, libinterp/corefcn/strfns.cc, libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc, libinterp/corefcn/urlwrite.cc, libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc, libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/colamd.cc, libinterp/octave-value/ov-bool-sparse.cc, libinterp/octave-value/ov-classdef.cc, libinterp/octave-value/ov-re-sparse.cc, libinterp/octave-value/ov-struct.cc, libinterp/parse-tree/pt-arg-list.cc, scripts/audio/@audiorecorder/play.m, scripts/audio/wavwrite.m, scripts/general/cart2sph.m, scripts/geometry/inpolygon.m, scripts/gui/listdlg.m, scripts/gui/msgbox.m, scripts/gui/private/message_dialog.m, scripts/help/get_first_help_sentence.m, scripts/help/lookfor.m, scripts/image/imshow.m, scripts/io/strread.m, scripts/java/javamem.m, scripts/miscellaneous/dir.m, scripts/miscellaneous/edit.m, scripts/miscellaneous/genvarname.m, scripts/miscellaneous/gzip.m, scripts/miscellaneous/private/__w2mpth__.m, scripts/plot/appearance/annotation.m, scripts/plot/draw/colorbar.m, scripts/plot/draw/quiver3.m, scripts/plot/util/hold.m, scripts/plot/util/print.m, scripts/polynomial/mkpp.m, scripts/polynomial/polyder.m, scripts/polynomial/spline.m, scripts/polynomial/unmkpp.m, scripts/signal/arma_rnd.m, scripts/sparse/gplot.m, scripts/statistics/tests/t_test.m, scripts/statistics/tests/t_test_regression.m, scripts/strings/mat2str.m, scripts/strings/strsplit.m, scripts/strings/strtrunc.m, scripts/strings/untabify.m, scripts/testfun/assert.m: maint: Remove unnecessary whitespace at end of lines.

## Copyright (C) 2010, 2013 Martin Hepperle
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn  {Function File} {@var{h} =} msgbox (@var{msg})
## @deftypefnx {Function File} {@var{h} =} msgbox (@var{msg}, @var{title})
## @deftypefnx {Function File} {@var{h} =} msgbox (@var{msg}, @var{title}, @var{icon})
## @deftypefnx {Function File} {@var{h} =} msgbox (@dots{}, @var{createmode})
## Display @var{msg} using a message dialog box.
##
## The message may have multiple lines separated by newline characters ("\n"),
## or it may be a cellstr array with one element for each line.
##
## The optional input @var{title} (character string) can be used to decorate
## the dialog caption.
##
## The optional argument @var{icon} selects a dialog icon.
## It can be one of @qcode{"none"} (default), @qcode{"error"}, @qcode{"help"},
## or @qcode{"warn"}.
##
## The return value is always 1.
##
## Compatibility Note: The optional argument @var{createmode} is accepted for
## @sc{matlab} compatibility, but is not implemented.
##
## @seealso{errordlg, helpdlg, inputdlg, listdlg, questdlg, warndlg}
## @end deftypefn

function retval = msgbox (msg, title = "", varargin)

  if (nargin < 1 || nargin > 4)
    print_usage ();
  endif

  retval = message_dialog ("msgbox", msg, title, varargin{:});

endfunction


%!demo
%! disp('- test msgbox message only.');
%! msgbox("Below, you should see 3 lines:\nline #1\nline #2, and\nline #3.");

%!demo
%! disp('- test msgbox message and caption.');
%! msgbox('You should see a single line.','A msgbox');