Hotfix: Undeprecate PhpEnvironement Response methods

Simply b/c facilities have been added so that Zend\Mvc can send responses does not remove the requirement that a PhpEnvironment\Response must be able to send itself.

Also, Zend\Http does not have a dependency on Zend\Mvc, so changes in behavior in Zend\Mvc should be of no consequence to Zend\Http.