Proportional scale image on auto thumbnail creation

The current version doesn't scale images proportionally on import. The images are cropped and then resized to the thumbnail proportion.

It's like to have it scale to the nearest, widest dimension. the assumption being if the image is taller than wide, it would match the height first and the width would be less than the max thunb size. If the image is wider than tall, it will match width and be shorter than thumb height.

thanks