Can support for the Google+ be added?

edit

Yes, it's easy. Just change askbot/skins/default/templates/question.html:

            {% if settings.ENABLE_SOCIAL_SHARING %}
            <a class="twitter-share" alt="{% trans %}Share this question on twitter{% endtrans %}"></a>
            <a class="fb-share" alt="{% trans %}Share this question on facebook{% endtrans %}"></a>
            <script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script>
            <g:plusone size="small" count="false"></g:plusone>
            {% endif %}

Note that this adds a javascript file from google. I've added this to my git fork.