Turn any template filter into a blocktag.

    Usage::

    {% load libs_tags %}
    {% block_anyfilter django.template.defaultfilters.truncatewords_html 15 %}
        // Something complex that generates html output
    {% endblockanyfilter %}

def block_anyfilter(parser, token):
    """
    Turn any template filter into a blocktag.

    Usage::

    {% load libs_tags %}
    {% block_anyfilter django.template.defaultfilters.truncatewords_html 15 %}
        // Something complex that generates html output
    {% endblockanyfilter %}

    """
    bits = token.contents.split()
    nodelist = parser.parse(('endblockanyfilter',))
    parser.delete_first_token()
    return BlockAnyFilterNode(nodelist, bits[1], *bits[2:])