Show the current JPEG compression ratio in the Save dialog

[ray_gurganus]

When saving a JPG image, I would suggest showing the current JPG quality compression % in the "Save" confirmation dialog. Since the last set % applies to all future images saved, this can prevent accidentally saving something at different % than intended. This is especially important when saving a lower % and intending it to be high, as this can result in an unusable image. It is easy to have changed the % on a previous save, forgotten about it, and the continued ahead thinking that this was set at something different than it actually is.