avoid connecting non existing signals from variable editor * gui-preferences-global.h: define object name for main window * main-window.cc (main_window): set object name for main window * octave-dock-widget.cc (label_dock_widget::label_dock_widget): connect copy/paste/undo signals only if parent is the main window

% Increase save size to run @seealso macro for Octave documentation
save_size = 10000