title: What is the proper way to move a UIDocument to a new location on the file-system
body: <p>I have a document-based iOS application with a <code>UIDocument</code> subclass. I need to be able to move the file it represents on the file-system. I have considered moving it with an <code>NSFileManager</code>, but this would mess up the <code>UIDocument</code>'s <code>fileURL</code> property. Any ideas on how to solve this little conundrum?</p>