title: RestyGWT and jerseyResponse is not Valid JSON document
body: <p>gwt 2.5 with Jersey 1.17 and RestyGWT 1.3</p>
  
  <p>when i call </p>
  
  <p>i get the following error:</p>
  
  <p>Could not parse response: org.fusesource.restygwt.client.ResponseFormatException: Response was NOT a valid JSON document</p>
  
  <p>my Resource class:</p>
  
  <pre><code>@Path("/person")
  public class PersonResource {
  
      private static int counter = 1;
  
      @GET
      @Produces(MediaType.TEXT_PLAIN)
      @Path("/hello")
      public String sayHello(){
          return "Hallo, Seryoga";
      }
  
      @GET
      @Produces(MediaType.APPLICATION_JSON)
      public Person getPersons() {
  
          List&lt;Person&gt; persons = new ArrayList&lt;Person&gt;();
          for (int i = 0; i &lt; 5; i++) {
              persons.add(new Person(counter, "name-" + counter, new Date()));
              counter++;
          }
  
          return persons.get(0);
      }
  }
  </code></pre>
  
  <p>client interface</p>
  
  <pre><code>public interface PersonResourceAsync extends RestService {
  
      @GET
      void getPersons(MethodCallback&lt;Person&gt; callback);
  
      /**
       * Utility class to get the instance of the Rest Service
       */
      public static final class Util {
  
          private static PersonResourceAsync instance;
  
          public static final PersonResourceAsync get() {
              if (instance == null) {
                  instance = GWT.create(PersonResourceAsync.class);
                  ((RestServiceProxy) instance).setResource(new Resource(
                          GWT.getHostPageBaseURL()+"rest/person"));
              }
              return instance;
          }
  
          private Util() {
  
          }
      }
  }
  </code></pre>
  
  <p>person class has some getter/setter for id name etc is serializable and @XmlRootElement</p>
  
  <p>my web.xml contains:</p>
  
  <pre><code>&lt;servlet&gt;
          &lt;servlet-name&gt;RestServlet&lt;/servlet-name&gt;
          &lt;display-name&gt;Rest Servlet&lt;/display-name&gt;
          &lt;servlet-class&gt;com.sun.jersey.spi.container.servlet.ServletContainer&lt;/servlet-class&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;com.sun.jersey.config.property.packages&lt;/param-name&gt;
              &lt;param-value&gt;digitronic.ems.server.filebrowser&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;com.sun.jersey.api.json.POJOMappingFeature&lt;/param-name&gt;
              &lt;param-value&gt;true&lt;/param-value&gt;
  
          &lt;/init-param&gt;
          &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
      &lt;/servlet&gt;
  </code></pre>
  
  <p>and in the projekt.gwt.xml:</p>
  
  <pre><code>&lt;!-- RestyGWT --&gt;
  &lt;inherits name='org.fusesource.restygwt.RestyGWT' /&gt;
  </code></pre>
  
  <p>when i call it via
  http:/localhost:8080/Projekt/rest/person i get the value in json syntax
  but via restygwt i calls onError and i dont know why.</p>
  
  <p>can some one help me?</p>