alfred: bump version to 2013.4.0

alfred: bump version to 2013.4.0

bump alfred to version 2013.4.0. From the CHANGELOG:

 * add new json output format for vis
 * add gps location information service for alfred
 * allow network interface to vanish and return without restart
 * allow to switch between master and slave operation without restart
 * renamed vis to batadv-vis to avoid collisions with other vis binaries
 * add manpages
 * various code cleanups
 * bugs squashed:

   * handle failing write() in unix sockets
   * Fix crash when vis opened empty file

alfred-gpsd is optional and requires libgps from the gpsd package to
compile. It needed its own -lm for libgps which does not link to libm
by itself, a patch for upstream alfred has been posted.

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>