These images are licenced under a double CC-SA (Creative Commons 
Attribution ShareAlike) and GPL licence (see file COPYING in that 
directory). These licences are such that when combined with other 
works the whole work should be under the GPL or CC-SA. So you cannot combine 
the images with other materials, for example a manual text if the manual 
text is under a licence that doesn't allows to be relicenced under the 
conditions of the GPL or the CC-SA. For example a manual licenced under 
the GFDL or the artlibre licence cannot be combined with the image.
