"Unified" diff renderer.
This class renders the diff in classic "unified diff" format.
Copyright 2004-2012 Horde LLC (http://www.horde.org/)
See the enclosed file COPYING for license information (LGPL). If you did not receive this file, see http://www.horde.org/licenses/lgpl21.
Author: Ciprian Popovici
Located at Horde/Text/Diff/Renderer/Unified.php