Fixed #2056 -- Escaped history messages in admin. Thanks, SmileyChris

        {% for action in action_list %}

        <tr>

            <th scope="row">{{ action.action_time|date:_("DATE_WITH_TIME_FULL") }}</th>

            <td>{{ action.user.username }}{% if action.user.first_name %} ({{ action.user.first_name }} {{ action.user.last_name }}){% endif %}</td>

            <td>{{ action.change_message}}</td>

            <td>{{ action.user.username }}{% if action.user.first_name %} ({{ action.user.first_name|escape }} {{ action.user.last_name|escape }}){% endif %}</td>

            <td>{{ action.change_message|escape }}</td>

        </tr>

        {% endfor %}

        </tbody>