maint: Use Octave coding conventions in libgui/ directory. * Table.cc, qt-graphics-toolkit.cc, documentation.cc, documentation.h, files-dock-widget.cc, find-files-dialog.cc, gui-preferences-cs.h, gui-preferences-dw.h, gui-preferences-ed.h, gui-preferences-ff.h, gui-preferences-mw.h, gui-preferences-sc.h, history-dock-widget.cc, file-editor-tab.cc, file-editor.cc, find-dialog.cc, octave-qscintilla.cc, main-window.cc, octave-dock-widget.cc, octave-qobject.cc, resource-manager.cc, set-path-dialog.cc, set-path-model.cc, settings-dialog.cc, settings-dialog.h, shortcut-manager.cc, tab-bar.cc, variable-editor.cc, workspace-model.cc, workspace-model.h, workspace-view.cc: Use Octave coding conventions in libgui/ directory.

--- a/libgui/graphics/Table.cc	Sat Jan 11 13:55:55 2020 -0800
+++ b/libgui/graphics/Table.cc	Sun Jan 12 09:33:21 2020 -0800
@@ -380,7 +380,7 @@
     SCANF_AND_CONVERT(int64, int64_t, "%" PRId64 " %n")
     SCANF_AND_CONVERT(uint64, uint64_t, "%" PRIu64 " %n")
 
-  #undef SCANF_AND_CONVERT
+#undef SCANF_AND_CONVERT
 
     else if (old_value.isnumeric () && ! old_value.isinteger ())
       {