Add Fabio image as alternative to Lena

Fabio is a nice gender-balancing variation on lena, introduced in 2012
See: http://www.claremontmckenna.edu/news/every-picture-tells-a-story/
and first use in http://arxiv.org/abs/1202.6429
along with original file on http://nuit-blanche.blogspot.co.uk/2012/03/let-there-be-only-one-fabio.html

Its cons: gray-scale only
Its pros:
* matches lena's type of features,
* is enough well known thanks to the noise arounds its first use,
* is gender-balancing and a step away from unconscious brogramming :)

Hope this will make it in!