test/DumpDatabase, ...: no g_thread_init() calls when GLib is disabled
configure.ac: improve database dependency checks

Abort if --enable-libmpdclient or --enable-upnp are used with
--disable-database, instead of ignoring the mismatch silently.
configure.ac: auto-disable plugins that require GLib when --disable-glib is used
fs/Charset: work around clang's -Wunused-const-variable

MPD_PATH_MAX_UTF8 is only used by GLib-specific code currently.
test/test_archive: don't use GLib
configure.ac: require xmlto for --enable-documentation
configure.ac: show DSD in result
configure.ac: add storage plugin section to result
decoder/ffmpeg: recognize MIME type audio/aacp
configure.ac: update VERSION_REVISION
configure.ac: prepare for 0.20
Set pulseaudio channel map to WAVE-EX

Pulseaudio expects clients to specify their channel-map if the
default (ALSA) map does not route the audio to the expected speakers.

Many Google results suggest dealing with this by re-routing the audio
channels with the appropriate ALSA plugin, but this will then simply
break any clients which expect the default ALSA mapping.

Virtually all media files and codecs, certainly flac, dca, a52, and of
course anything based on Microsoft's WAVEFORMAT_EXTENSIBLE specification,
assume the layout in the table here:
http://en.wikipedia.org/wiki/Surround_sound#Standard_speaker_channels

Fortunately, pulseaudio directly addresses this with a built-in channel
map for WAVE-EX which can be set automatically in the stream sample-spec.