[WIP] NL-means denoising

Following a message on the mailing-list, here is a first attempt at contributing my non-local means denoising code. It still lacks an example for the gallery. I would also welcome suggestions to improve the speed, since this algorithm is very slow...
Yes for example on http://dmi.uib.es/~tami/publicacions/cvpr.pdf

Google scholar actually proposes about 20 different links from which a pdf can be downloaded. The problem is that such links can disappear overnight... Do you think we should link to a preprint? I would search for pdfs on Google Scholar anyway...