This reverts commit f0be48ff
(except for the NEWS entry).

If libdispatch (GCD) is used before forking, it
can't safely be used again after forking.

Negating an unsigned integer does not work.

Works around the "PCM conversion from f to dsd is not implemented"
error message that prevents DSD playback.

Many years ago, FAAD had a serious ABI bug: the NeAACDecInit()
prototype in its header declared the "samplerate" parameter to be
"unsigned long *", but internally, the function assumed it was
"uint32_t *" instead.  On 32 bit machines, that was no difference, but
on 64 bit, this left one portion of the return value uninitialized;
and worse, on big-endian, the wrong word was filled.  This bug had to
be worked around in MPD (commit 9c4e97a6).

A few months later, the bug was fixed in the FAAD CVS in commit 1.117
on file libfaad/decoder.c; the commit message was:

 "Use public headers internally to prevent duplicate declarations"

The commit message was too brief at best; the problem was not
duplicate declarations, but a prototype mismatch.  No mention of the
bug fix in the ChangeLog.

The MPD project never learned about this bug fix, and so MPD would
always pass a "uin32_t *" dressed up as a "unsigned long *".  Nearly 6
years later, it's about time to fix this second ABI problem.  Let's
kill the workaround!

MPD_PATH_MAX_UTF8 is only used by GLib-specific code currently.

Abort if --enable-libmpdclient or --enable-upnp are used with
--disable-database, instead of ignoring the mismatch silently.

Fixes memory leak because ao_plugin_close() never gets called.

Be consistent.

A mutex acts as a memory barrier, and thus "volatile" is not
necessary.

Use the "_format" parameter instead of the (uninitialized) "format"
attribute.

Report unsupported format while opening the filter, not later when the
first conversion takes place.

Fixes assertion failure in destructor by not assigning
{src,dest}_format when an error occurs.

Fixes truncated lines in m3u and cue files (regression by commit
67958f7f).

The file systemd/mpd.service.in is being distributed implicitly, but
systemd/mpd.socket is not and needs to be added to EXTRA_DIST.

Fixes deadlock bug in the "mms" plugin.

Export it from the protected base class.  This fixes a build failure
on Mac OS X.