CON-2255 | Venus recommendations images "face detection"

Ported imageServing "face detection" to js module

~~Update ```vignete.js``` to stable version before merging. Stable version doesn't support vignette urls. This version is taken from https://github.com/Wikia/vignette-js/pull/16 + temporary fixed https://github.com/Wikia/vignette-js/issues/17~~ - done