Replaced myFgets() with fgets() + g_strchomp().

g_ascii_isspace() includes \r and \n.  This means that lines from a
text file don't have to be chopped prior to buffer2array().

Don't do two allocations for the mod_Data structure.

The log file is duped to STDOUT_FILENO and STDERR_FILENO.  No need to
keep another copy of it in out_fd all the time.  We only need it once
once in setup_log_output().

When MPD exits, it should manually free all resources in use, to allow
easy memory leak debugging.  Make the decoder thread terminate during
that.

Allow logging to syslog if log_file is configured to "syslog".

Added log_init_file() and log_init_stdout(), preparing for other
logging targets.

The logging library currently has 3 constructor functions: initLog(),
open_log_files(), setup_log_output(), called in this order.  Merged
the first two.

Declare log_threshold as GLogLevelFlags.

If the user wants the log files with a specific mode, he has to start
MPD with the correct umask.  Don't hard-code that.

This fixes a bug: when log cycling failed, MPD would not restore the
old umask.

Merged code from open_log_files() and cycle_log_files().

Removed the "error_file" option.  There is only one log file now.  If
a user wants to see only the errors, he should configure a log_level.

This patch adds RVA2 (relative volume adjustment) tag
support to mpd, as a fallback if no replaygain tags are
found. The code is almost directly from madplay (GPL).

RVA2 tags are generated for example by the "normalize" utility.

Updated by: Avuton Olrich <avuton@gmail.com>

Use GLib locking (GMutex, GCond) instead of pthread because GLib is
more portable, e.g. on mingw32.

Don't use NOTIFY_INITIALIZER to initialize audio_output_client_notify.

Build the path with g_build_filename().  Also use g_get_home_dir() and
g_file_test().

Eliminate duplicated code.  The GLib code is much more mature than
MPD's custom parser.

Prepare for the migration to the GLib option parser, which uses
gboolean for flags.

The input_stream object should only be closed by the MPD core
(i.e. decoder_thread.c / decoder_run()).  A decoder plugin which
attempts to close it will result in a segmentation fault.