Pimage blur

A serviceable blur implementation. It is pretty much a port of the java-processing implementation. Results are not exactly the same for the given radius but it is pretty decent (this impl needs a higher radius to achieve the same blurriness). Not exactly sure what causes the difference though (i'm guessing differences in math routines somewhere, but maybe i overlooked something). I'd say its somewhere in-between what processing and photoshop produce given the same image.

Example is viewable in filter-images.html.