Bug 591005 - Add AFC backend

Add a backend based on libiphone to access data on Apple's iPhone,
and iPod Touch.

Code by:
Patrick Walton <pcwalton@cs.ucla.edu>
Martin Szulecki <opensuse@sukimashita.com>
Nikias Bassen <nikias@gmx.li>
Bastien Nocera <hadess@hadess.net>

http://bugzilla.gnome.org/show_bug.cgi?id=591005