Description:
------------
version 1.0.2 is missing the "SOLR_PHP_SERIALIZED_RESPONSE_WRITER". the constant is defined but there is no usage of the "phps" response format, only for the "phpnative".


Test script:
---------------
$solrClient = new SolrClient(array(
  'hostname' => "localhost",
  'port'     => 8983,
  'path'     => 'solr/core0',
  'wt'       => 'phps'
);
$query = new SolrQuery();
$solr->query("*:*");

Expected result:
----------------
no warning and parsed result using phps sourc.

Actual result:
--------------
Warning: Unsupported response writer phps. This value will be ignored.