title: Set minimum zoom level for UIImagePickerController cropping
body: <p>I am using a UIImagePickerController to allow the user to upload a photo for use in my application. After selecting a photo to upload, the user is then prompted to crop his/her photo (since I have set <code>imagePickerController.allowsEditing = YES</code>). However, if the photo is landscape (i.e., wider than it is taller), it is currently possible for the user to crop the photo in a way that does not output a square image. This is because the default zoom level when cropping landscape photos is aspectFit rather than aspectFill (as it is for portrait photos).</p>
  
  <p>Is it possible to set the minimum zoom level for UIImagePickerController's edit mode? I suppose I could simply automatically crop the image if the output is not square, but I would rather that the edit mode of UIImagePickerController convey this to the user instead of doing it for him/her.</p>