Add support for localparams for queries

[lafka]

Add support for local params as described in http://wiki.apache.org/solr/LocalParams

This allows for tagging queries for faceting ( http://wiki.apache.org/solr/SimpleFacetParameters#Multi-Select_Faceting_and_LocalParams )

        {def $search_data = fetch(
                'ezfind', 'search', hash(
                    'query',    '*:*',
                    'class_id', 'artwork',
                    'limit',    $searchCountData.SearchCount,
                    'facet',  array(
                        hash(
                            'field',   '{!ex=am\}artwork/medium',
                        ),
                    ),
                    'filter', $searchFilter,
                    'group', hash(
                        'field',    '{!tag=am\}artwork/medium',
                        'truncate', 'true',
                        'main',     'true',
                    ),
                )
            )
        }