new image processing module. This module needs libAfterImage

(http://afterstep.sourceforge.net/afterimage/) to run. The initial prototype
was made by me, but it has been largely extended by Reiner Rohlfs from
ISDC who added many new features of interest to the astrophysics community.
This is a first release and many things can cleary be added and improved.
Looking forward to feedback and contributions.


git-svn-id: http://root.cern.ch/svn/root/trunk@5097 27541ba8-7e3a-0410-8455-c3a389f83636