Edit script

def edit_script(self, filename=None, goto=-1):
        """Edit script"""
        # Called from InternalShell
        if not hasattr(self, 'main') \
           or not hasattr(self.main, 'editor'):
            self.shell.external_editor(filename, goto)
            return
        if filename is not None:
            self.edit_goto.emit(osp.abspath(filename), goto, '')