buildroot

fastd: bump to v18

Release notes at http://fastd.readthedocs.org/en/v18/releases/v18.html

First patch rebased, second patch removed (gone upstream). Using tarball
and hashes instead of git now.

Signed-off-by: Alexander Dahl <post@lespocky.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>