Redmine

The attached patch overwrites some images in the public/images folder with images processed
by the ysmush.it service at

http://www.smushit.com/ysmush.it/

This shrinks them by ~30% at no loss in quality. (There are also additional images it converted from other formats to .png to save even more space, but I didn't include those.)

I would greatly appreciate if this could be merged into the mainline.

Thanks