title: readEntity affected by json_class?
body: <p>Does the "json_class" attribute have some special meaning?  I have 2 get/post sets and that is the only signficant difference in the json.  The first set worked great.  I was able to use:</p>
  
  <pre><code>MyResponseClass mrc = client
                      .target(urlWithParams)
                      .request(MediaType.APPLICATION_JSON)
                      .header("access_token", accessToken)
                      .get()
                      .readEntity(MyResponseClass.class);      
  </code></pre>
  
  <p>The second set won't work unless i break into 2 parts (ie read into Reader and then map to object). The only significant difference I see is the first attribute in the second json is always "{"json_class":"Message","broadcast":false,"content":"post from java 1","created_at":"2013-08-14T12:31:03-05:00","deleted":false,"....}</p>
  
  <pre><code> java.io.Reader reader = client
                      .target(urlWithParams)
                      .request(MediaType.APPLICATION_JSON)
                      .header("access_token", accessToken)
                      .get()
                      .readEntity(java.io.Reader.class);       
  
  THEN I can parse
     ObjectMapper mapper = new ObjectMapper();        
     MyResponseClass response = mapper.readValue(reader, MyResponseClass.class);  
  </code></pre>
  
  <p>But if I use the code from the first set it throws a "MessageBodyReader not found for media type=text/html; charset=utf-8, ..." exception.</p>