title: Pig. JsonLoader. Load nested objects without schema
body: <p>I have jsons and I want to load it to pig. Each json looks like this:</p>
  
  <pre><code>{"timeStamp":1397718396509,"requestUid":"534F7D320007","result":
  {//many many different objects}
  </code></pre>
  
  <p>And I can't provide schema for field <em>result</em> because it's not constant and it's very big. So I want to load it as a chararray, or map, or something - doesen't matter. But it should be loaded because it will be needed later. I've tried something like this:</p>
  
  <pre><code>LOAD 'log' USING JsonLoader('timestamp:long, req_id:chararray, result:chararray');
  </code></pre>
  
  <p>But I get an empty <em>result</em> field. What is the simplest way to achieve what I want?</p>