autogen.sh:
Detect more strange paths for aclocal on different
packaging systems.  This should help encourage more
people to run svn code on their systems.

configure.ac:
Tested on FreeBSD (6.1).  Darwin, OpenBSD, NetBSD info
gleaned off the Makefile distributed with git.

m4/shout.m4:
The Shout 2.2 port on a FreeBSD 6.1 machine seemed
problematic when it's compiled against pthreads, so this is
a gross hack to force -lpthread on it

git-svn-id: https://svn.musicpd.org/mpd/trunk@4390 09075e82-0dd4-0310-85a5-a0d7c8717e4f