message: Correct offset when copying view to image
diff: @@ -539,7 +539,7 @@ impl<I> SubImage<I> {
  for y in 0..self.ystride {
  for x in 0..self.xstride {
  - let p = borrowed.get_pixel(x, y);
  + let p = borrowed.get_pixel(x + self.xoffset, y + self.yoffset);
  out.put_pixel(x, y, p);
  }
  }
  @@ -627,10 +627,13 @@ mod tests {
  fn test_can_subimage_clone_nonmut() {
  let mut source = ImageBuffer::new(3, 3);
  source.put_pixel(1, 1, Rgba([255u8, 0, 0, 255]));
  +
  + // A non-mutable copy of the source image
  let source = source.clone();
  + // Clone a view into non-mutable to a separate buffer
  let cloned = source.view(1, 1, 1, 1).to_image();
  - assert!(cloned.get_pixel(0, 0) == source.pixel(1, 1));
  + assert!(cloned.get_pixel(0, 0) == source.get_pixel(1, 1));
  }
  }
  