By default, glibc 2.8 hides struct ucred behind the _GNU_SOURCE
macro.  I don't want to enable that globally, because it may encourage
the use of non-portable functions.  Test if "struct ucred" is
available, and enable _GNU_SOURCE if required.

For details about that issue, see glib's bug database:

 http://sources.redhat.com/bugzilla/show_bug.cgi?id=6545

Detect the following libraries with pkg-config: libshout, libid3tag,
libmad.

This patch fixes several imports to use pkg-config instead of certain
esoteric tests.

This is needed for people that don't use any of the following:
JACK, ALSA, libmikmod, Shout.

[mk: moved this patch after "Refactor and cleanup of shout Ogg and MP3
audio outputs".  The original commit message follows, although it is
outdated:]

Creation of shout_mp3 audio output plugin. Basically I just copied the
existing shout plugin and replaced ogg with lame. Uses lame for mp3
encoding. Next step is to pull common functionality out of each shout
plugin and share it between them.

Configuration options for "shout_mp3" are the same as for "shout".

Previously, it was not possible to check for e.g. "-std=c99".

needed for compatibility with older gcc.  Also, threw in
some warnings for things I find offensive
(declaration-after-statement, shadow)

git-svn-id: https://svn.musicpd.org/mpd/trunk@7299 09075e82-0dd4-0310-85a5-a0d7c8717e4f

argument.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6324 09075e82-0dd4-0310-85a5-a0d7c8717e4f

We will restore compatibility with the old API in the
next few commits; along with OggFLAC support.

git-svn-id: https://svn.musicpd.org/mpd/trunk@5110 09075e82-0dd4-0310-85a5-a0d7c8717e4f

They still won't be able to get pulse without pkg-config, however.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4774 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@4763 09075e82-0dd4-0310-85a5-a0d7c8717e4f

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

git-svn-id: https://svn.musicpd.org/mpd/trunk@4352 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@3926 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@3066 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@3061 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@2916 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@2655 09075e82-0dd4-0310-85a5-a0d7c8717e4f