open editor tab and insert marker for debugging with gui * file-editor-interface.h (file_editor_interface::request_open_file): New public slot. (file_editor_interface::handle_dbstop_request): New virtual function. * file-editor-tab.h, file-editor-tab.cc (file_editor_tab::goto_line): New arg, line, with default value. Don't prompt if line is greater than zero. (file_editor_tab::set_debugger_position): New arg, widget id. (file_editor_tab::add_filename_to_list): New arg, widget id. * file-editor.h, file-editor.cc (file_eidtor::editor_tab_map): New data member. (file_editor::fetFileNames) Delete. (file_editor::~file_editor, file_editor::check_conflict_save, file_editor::handle_add_filename_to_list): Use editor_tab_map instead of fetFileNames. (file_editor::request_open_file): New args, line and set_marker. Optionally position cursor at line and with debug marker. If file is already open in tab, switch to it instead of giving error. (file_editor::construct): Connect fetab_set_debugger_position signal to set_debugger_position slot. * main-window.h, main-window.cc (main_window::dbstop_signal): New signal. (main_window::handle_dbstop_request): New function. * octave-event-listener.h (octave_event_listener::dbstop): New virtual function. * octave-qt-event-listener.h, octave-qt-event-listener.cc (octave_qt_event_listener::dbstop): New function. (octave_qt_event_listener::dbstop_signal): New signal. * octave-link.h, octave-link.cc (octave_link::dbstop, octave_link::do_dbstop, octave_link::dbstop_event_hook_fcn, octave_link::do_dbstop_event_hook_fcn): New functions * octave-main-thread.h, octave-main-thread.cc (dbstop_event_hook_fcn): New function. (octave_main_thread::run): Add it to the list of dbstop event hook functions.

--- a/libgui/src/m-editor/file-editor-tab.h
+++ b/libgui/src/m-editor/file-editor-tab.h
@@ -75,9 +75,9 @@
   void comment_selected_text (const QWidget* ID);
   void uncomment_selected_text (const QWidget* ID);
   void find (const QWidget* ID);
-  void goto_line (const QWidget* ID);
+  void goto_line (const QWidget* ID, int line = -1);
 
-  void set_debugger_position (int line);
+  void set_debugger_position (const QWidget *ID, int line = -1);
 
   void set_modified (bool modified = true);
 
@@ -90,7 +90,7 @@
   void file_name_changed (const QString& fileName, const QString& toolTip);
   void editor_state_changed (bool copy_available, const QString& fileName);
   void tab_remove_request ();
-  void add_filename_to_list (const QString& fileName);
+  void add_filename_to_list (const QString&, QWidget *);
   void mru_add_file (const QString& file_name);
   void editor_check_conflict_save (const QString& saveFileName, bool remove_on_success);
   void process_octave_code (const QString& command);