graphics/lux: Add new port

lux is an image viewer for 'normal' images and the most common types of
panoramic images, typically showing a 'rectilinear' view to the image
data, which looks as if this view had been taken with an 'ordinary'
lens. The view can be zoomed, panned, scrolled, rotated and modified in
several ways. lux displays images, it does not modify them. But it can
produce high-quality images from the view it shows. lux can also
produce synoptic views of several images and do stitching, HDR blending,
exposure fusions, focus stacks and deghosting, usually from 'PTO' files,
processing a subset of the panotools standard used by panorama stitching
software like hugin.

WWW: https://bitbucket.org/kfj/pv

PR: 262943