This contribution gives you the following features:
* Cached thumbnails in catalog for faster loading times.
* Tweakable for having thumbnails created with a transparent backgrounds.
* Saves cached thumbnails in a separate folder (easy for cleaning up).
* Unique md5 thumbnail filenames such as e0f8ab89c52355e107326293f64e6f25_100x80.jpg based on md5("path/to/file.ext").
Caution! This may collide with other image management contributions.