title: namespace prefixes with jackson
body: <p>So im using Jackson 2.9.3 with Woodstox.</p>
  
  <p>i can define xmlns with this java annotation:</p>
  
  <pre><code>@JacksonXmlRootElement(localName = "metadata", namespace = "http://purl.org/dc/elements/1.1/")
  public class Metadata {
  </code></pre>
  
  <p>resulting in this on deserialization:</p>
  
  <pre><code>&lt;metadata xmlns="http://purl.org/dc/elements/1.1/"&gt;...&lt;/metadata&gt;
  </code></pre>
  
  <p>And this is working as intended.</p>
  
  <p>But <strong>how</strong> is it possible to achieve a namespace prefix like this:</p>
  
  <pre><code>&lt;metadata xmlns:dc="http://purl.org/dc/elements/1.1/"&gt;
      &lt;dc:title id="title"&gt;Recollections of Wartime&lt;/dc:title&gt;
  </code></pre>
  
  <p>so there should be a namespace-prefix defined in the root element: <strong>xmlns:dc</strong> = "..."</p>
  
  <p>and child tags/attributes should be able to use that prefix: &lt;<strong>dc</strong>:title></p>
  
  <p>Is that possible with jackson/woodstox?</p>