title: NSURL object from initWithString gives -[NSURL length] error
body: <p>I'm trying to find a file with a path, then delete it using the NSFileManager class. the <code>[info objectForKey:UIImagePickerControllerMediaURL]</code> does return a string, so I dont' understand why its failing on a valid parameter. </p>
  
  <pre><code>NSError *error;
  
  NSFileManager *manager = [NSFileManager defaultManager];
  
  NSURL *url = [[NSURL alloc] initWithString:[info
                objectForKey:UIImagePickerControllerMediaURL]];
  
  
  if ([manager isDeletableFileAtPath: [info 
                    objectForKey:UIImagePickerControllerMediaURL]]) {
      BOOL success = [manager removeItemAtURL:url error:&amp;error];
      if (!success) {
          NSLog(@"Error removing file at path: %@", error.localizedDescription);
      }
  }
  </code></pre>
  
  <p>And I get this error:</p>
  
  <pre><code>*** Terminating app due to uncaught exception 'NSInvalidArgumentException'
     , reason: '-[NSURL length]: unrecognized selector sent to instance 0x175ede10'
  </code></pre>