But if you zoom into the image because you want to align the crop to an image-element, it may happen that the handles are off-screen:
Suggestion:
* either make the position of the handles "dynamic" so that every visible crop-border offers one visible handle
or
* make the whole border act as a handle.
currently grabbing the border just moves the whole frame, which is nice but useless since moving can already be easily accomplished by grabbing anywhere inside the crop-frame.
