preserve pending command line input when running commands from GUI actions * QTerminal.h, QTerminal.cc (QTerminal::relay_command): Delete. * file-editor-tab.cc (file_editor_tab::run_file_callback): New argument, bp_info. Save pending command line input and execute command. (file_editor_tab::run_file): Use octave_link to execute file. * main-window.h, main-window.cc (main_window::execute_command_in_terminal): Rename from main_window::handle_command_double_clicked. Post event through octave_link to execute command. (main_window::construct_octave_qt_link): Connect _octave_qt_link::execute_command_in_terminal_signal to main_window::execute_command_in_terminal. (main_window::execute_command_callback): New function. (main_window::relay_command_signal): Delete signal. Remove all uses. * octave-qt-link.h, octave-qt-link.cc (octave_qt_link::do_execute_command_in_terminal): New function. (octave_qt_link::execute_command_in_terminal_signal): New signal. * terminal-dock-widget.h, terminal-dock-widget.cc (terminal_dock_widget::relay_command_signal): Delete signal. Remove all uses. * octave-link.h (octave_link::execute_command_in_terminal, octave_link::do_execute_command_in_terminal): New functions. * cmd-edit.h, cmd-edit.cc (command_editor::pre_input_hook_set): New variable. (gnu_readline::previous_pre_input_hook, command_editor::intial_input): New member variables. (command_editor::restore_pre_input_hook, command_editor::do_get_current_line, command_editor::do_replace_line, command_editor::set_pre_input_hook, gnu_readline::do_get_current_line, gnu_readline::do_replace_line, gnu_readline::set_pre_input_hook, command_editor::set_initial_input, gnu_readline::restore_pre_input_hook, default_command_editor::do_get_current_line, default_command_editor::do_replace_line, command_editor::insert_initial_input, command_editor::pre_input_handler, command_editor::get_current_line, command_editor::replace_line, command_editor::add_pre_input_hook, command_editor::do_insert_initial_input, command_editor::set_pre_input_hook, command_editor::restore_pre_input_hook): New functions. (command_editor::readline): Handle initial input. (command_editor::interrupt): Give argument a default value. * oct-rl-edit.h, oct-rl-edit.c (octave_rl_copy_line, octave_rl_replace_line, octave_rl_set_pre_input_hook, octave_rl_get_pre_input_hook): New functions. (rl_pre_input_hook_fcn_ptr): New typedef.