'Show kernel restarted/died messages.'

@Slot(str)
def kernel_restarted_message(self, msg):

    try:
        stderr = codecs.open(self.stderr_file, 'r', encoding='utf-8').read()
    except UnicodeDecodeError:
        try:
            stderr = self._read_stderr()
        except:
            stderr = None
    except (OSError, IOError):
        stderr = None
    if stderr:
        self.show_kernel_error(('<tt>%s</tt>' % stderr))
    else:
        self.shellwidget._append_html(('<br>%s<hr><br>' % msg), before_prompt=False)
