URL parameters for images in 0.9.1?

[LonelyPixel]

What are all those URL parameters in the images in CSS files good for that were added with 0.9.1?

Every time I upgrade to a new version, I need to update my skin copy as well and the more changes there are, the less fun it is... I'm thinking about not applying these URL parameters as they don't have any obvious effect anyway.

[JohnDoh]

they are for cache busting (if an image is changed the params will change so the user gets the new image and not an old cached one). they are added by the bin/updatecss.sh script for releases.