Win32 has many audio APIs. New name is slightly more correct.

This cleanup call is obsolete, since we moved the binding code to
enable()/disable().

Call output_plugin.disable() before output_plugin.finish().  This
ensures that all outputs are properly cleaned up, to make valgrind
happy.

Original implementation does not handle
	if (...)
		MPD_ERROR("die");
	else
		...
case well. This change fixes handling of such cases.

Replaced all occurrences of g_error() with MPD_ERROR() located in a new header
file 'mpd_error.h'. This macro uses g_critical() to print the error message
and then exits gracefully in contrast to g_error() which would internally call
abort() to produce a core dump.

The macro name is distinctive and allows to find all places with dubious error
handling. The long-term goal is to get rid of MPD_ERROR() altogether. To
facilitate the eventual removal of this macro it was added in a new header
file rather than to an existing header file.

This fixes #2995 and #3007.

Added support for a new optional configuration setting for the httpd output
named "bind_to_address". Setting it to a specific IP address (v4 or v6) will
cause the httpd output to bind to that address exclusively. Supporting
multiple addresses in parallel is future work.

This implements the feature requests #2998 and #2646.

The check was meant to fix an assertion failure, but it was the wrong
way around.  This broke cross-fading most of the time.

According to the mantis bug report 2847, there are several possible
variations of the "album artist" tag:

- "album artist"
- "album_artist"
- "albumartist"

This patch adds support for the latter two.

I've added PIPE_EVENT_SHUTDOWN because calling g_main_loop_quit() do not work when called from another thread.
Main thread was sleeping in g_poll() so I needed some way to wake it up.

By some strange reason call close(event_pipe[0]) in event_pipe_deinit() hangs.
In current implementation that code never reached so that was not a problem :-)
I've added a conditional to leave event_pipe[0] open on Win32.

An '\n' was erroneously inserted in the line containing the state, e.g.
"state: \nplay" instead of "state: play".

Fix for bug #2992.

htons() is not available if netinet/in.h is not included.

Fix gcc warning.

Work around aliasing warning.

Be consistent with the rest of MPD, and don't use the non-portable
header "malloc.h".

Fixes duplicate playlist entries.

False if the vector was not modified.

Send silence to all connected clients while paused, to avoid
connection interruption.

Avoid buffer underruns on the streaming client, if the encoder is "too
efficient" (e.g. when encoding silence while paused).

The ReplayGain filter clamped the gain to max. 100 % even if the
algorithm determined the signal needed a boost. That would result in any
such tracks being played with too low volume, effectively defeating the
purpose of the filter.

Unfortunately, there's no "optimized" implementation here.  We can't
use Linux's proprietary system call dup3(), because it would require
us to specify the new descriptor.