We never used many features from it, so there's no point in
keeping it and forcing people to install a non-standard library.
It may be standard on many GNU/Linux distributions, but there
are many other UNIXes out there.  This makes life much easier
for people cross-compiling (like me :)

git-svn-id: https://svn.musicpd.org/mpd/trunk@4361 09075e82-0dd4-0310-85a5-a0d7c8717e4f