title: ALAssetPropertyDate returns "wrong" date
body: <p>I'm currently working on a project in which i need to read some (Latitude, Longitude and date ) EXIF data. The location data seems correct, but the date i'm getting seems to be the "date last modified" date. </p>
  
  <pre><code>{
      CLLocation *loc = [asset valueForProperty:ALAssetPropertyLocation];
      NSDate *date = [asset valueForProperty:ALAssetPropertyDate];
      //Returns Last modified date(Picture was taken ... let's say september 
      //last year and it would return the date and time I 'modified' the image).
      NSString *latitude  = [NSString stringWithFormat:@"%g",loc.coordinate.latitude];//Returns correct Latitude
      NSString *longitude = [NSString stringWithFormat:@"%g",loc.coordinate.longitude];//Returns correct Longitude
  }
  </code></pre>
  
  <p>My question is: Am i doing something terribly wrong, or is this expected behavior. 
  I also tried to use the <code>loc.timestamp</code> instead of the <code>[asset valueForProperty:ALAssetPropertyDate]</code> but these returned the same date.
   Any help is greatly appreciated ! </p>