changelog: add an attribution. whoops.

      in feh is no longer required. For a slight speed-up, or to use feh with

      an affected Imlib2 version (1.6.x or 1.7.0), compile feh with 'magic=1'.

      In this case, feh will use libmagic to determine whether a file is an

      image, and only pass images to Imlib2.

      image, and only pass images to Imlib2. (Patch by Christian Hesse)

    * Fix crash (segmentation fault due to null pointer dereference) when

      toggling fullscreen mode while moving the cursor.

    * Note that feh no longer supplies its own getopt_long function.