Edismax Query Support Support

We can use `edismax` and `boost`.

    var query = solr.createQuery()
                .q(queryString)
                .edismax()
                .boost('product(<field_name>, <some_integer>)')
                .start(skip)
                .rows(count);

p.s. `boost` is multiplicative version of `bf` and available for `edismax` only