[wp-testers] new: multiple custom image sizes - patch needs testing and feedback

[Leo germani]

New patch (3). Retroactive image reprocessing

Added the regenerate all thumbnails funcionality

1. I did without ajax (at least for the moment). When I finished it I didnt
see so much the need for an ajax alternative

2. I created a function called wp_update_thumbs - I though it was worth to
have it so we can use in other places in the code, such as in the manage
media page, I think there could be there a button to regenerate the thumbs
for each image. It could be a button for each image and a bulk action

3. It patches the new "Edit Image" feature too
Leo,,