title: deep copy object array properties value with jQuery
body: <p>Take a look at this snippet:</p>
  
  <pre><code>$.extend( true, {}, { key: ["somevalue"] }, { key: ["anothervalue"] })
  </code></pre>
  
  <p>doing this I expect the produced object will contain a property called "key"
  which is an array and has 2 elements, e.g</p>
  
  <pre><code>{ key: ["somevalue", "anothervalue"] }
  </code></pre>
  
  <p>Am I just giving the deep copy more than it can handle?</p>