eliminate unnecessary uses of octave_qobject in GUI classes * BaseControl.cc, BaseControl.h, ButtonControl.cc, ButtonControl.h, ButtonGroup.cc, ButtonGroup.h, Canvas.cc, Canvas.h, CheckBoxControl.cc, CheckBoxControl.h, Container.cc, Container.h, ContextMenu.cc, ContextMenu.h, EditControl.cc, EditControl.h, Figure.cc, Figure.h, GLCanvas.cc, GLCanvas.h, ListBoxControl.cc, ListBoxControl.h, Menu.cc, Menu.h, Object.cc, Object.h, Panel.cc, Panel.h, PopupMenuControl.cc, PopupMenuControl.h, PushButtonControl.cc, PushButtonControl.h, PushTool.cc, PushTool.h, RadioButtonControl.cc, RadioButtonControl.h, SliderControl.cc, SliderControl.h, Table.cc, Table.h, TextControl.cc, TextControl.h, ToggleButtonControl.cc, ToggleButtonControl.h, ToggleTool.cc, ToggleTool.h, ToolBar.cc, ToolBar.h, ToolBarButton.cc, ToolBarButton.h, annotation-dialog.cc, annotation-dialog.h, qt-graphics-toolkit.cc, qt-graphics-toolkit.h, command-widget.h, community-news.cc, community-news.h, documentation-bookmarks.cc, documentation-bookmarks.h, documentation.cc, external-editor-interface.cc, external-editor-interface.h, find-files-dialog.cc, find-files-dialog.h, graphics-init.cc, graphics-init.h, interpreter-qobject.cc, file-editor.cc, find-dialog.cc, find-dialog.h, main-window.cc, main-window.h, news-reader.cc, news-reader.h, octave-qobject.cc, release-notes.cc, resource-manager.cc, set-path-dialog.cc, set-path-dialog.h, shortcut-manager.cc, shortcut-manager.h, welcome-wizard.cc, welcome-wizard.h, workspace-model.cc: Don't store references to octave_qobject in GUI classes where it is no longer needed. Eliminate unnecessary octave_qobject constructor arguments. Change all uses.

%!function [raa, rbb, igaa, igbb] = sub1 (aa, bb)
%!  global aa bb;
%!  aa = 1;
%!  raa = aa;
%!  rbb = bb;
%!  igaa = isglobal ("aa");
%!  igbb = isglobal ("bb");
%!endfunction

%!test <*53579>
%! global aa bb;
%! assert (isglobal ("aa"));
%! assert (isglobal ("bb"));
%! aa = 3;
%! xx = 5;
%! [raa, rbb, igaa, igbb] = sub1 (aa, xx);
%! assert (raa, 1);
%! assert (rbb, []);
%! assert (igaa);
%! assert (igbb);
%! assert (xx, 5);
%! clear -global aa bb;  # cleanup after test