When client_defer_output() aborts the connection to the client,
client_write_output() called client_write_deferred() anyway.  This
caused an assertion failure.  Fix it by checking for the "expired"
flag again after client_defer_output() returns.

I'm hunting down a bug where client->channel==NULL during I/O
operations.  These new assertions help avoid this kind of bug in the
future.

This patch fixes a memory leak: the fifo_buffer object was not freed
when the client connection was closed.

On both locations, the result of write() can be ignored safely.  In
event_pipe_emit_fast(), that can only be "EAGAIN", which means that
the pipe buffer is full - no further notification required.  In
client_init(), that would be a fatal connection error, which would be
caught by the next event.

This patch fixes gcc warnings.

This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.

Removed the sockaddr_to_tmp_string() hack, use
the new function sockaddr_to_string() instead.

Since we introduced a GLib logging domain, the "client" string appears
twice in the log lines:

 client: client 0: command returned 0

Removed the second one, now it looks like this:

 client: [0] command returned 0

Still not quite good, but better than before.

When we do not explicitly catch G_IO_ERR and G_IO_HUP, GLib can go
into an infinite loop, because it won't deliver the socket error to
MPD.

GIOChannel is more portable than raw read()/write() calls.  We're
using GIOChannel anyway, because we need it for plugging the client
into the GLib main loop.

Configure the GIOChannel to the bare minimum: no character set, no
buffering.

Use g_io_channel_win32_new_socket() instead of g_io_channel_unix_new()
on WIN32.

On some platforms, g_free() must be used for memory allocated by
GLib.  This patch intends to correct a lot of occurrences, but is
probably not complete.

Simplify some code by using config_get_positive(), instead of doing
manual parsing and validation each time.

Renamed functions, types, variables.

Get rid of the non-portable Linux list library, part I.

The length of GREETING is known at compile time, don't use strlen().

We are going to migrate away from the concept of notifying the main
thread.  There should be events sent to it instead.  This patch starts
a series to implement that.

With the GLib main loop, the client manager can install its own event
in case a client is expired.  No need for main.c to call
client_manager_expire() manually.

Remove the event source from the GMainLoop object in
client_set_expired().

Other libraries may need to access the main_loop reference, to add or
remove events, or to call g_main_loop_quit().

This is a rather huge patch, which unfortunately cannot be splitted.

Instead of using our custom ioops.h library, convert everything to use
the GLib main loop.

On Windows, socket declarations reside in winsock.h and ws2tcpip.h.
The POSIX headers sys/socket.h etc. are not available.

When a response is very long (e.g. a large playlist > 100k songs),
most of it will end up in the deferred buffers.  Filling the deferred
queue is very expensive currently, because a new buffer is allocated
for every client_write() operation.  This may lead to long delays, and
the client might give up and disconnect meanwhile.  This patch makes
MPD attempt to flush the deferred queue as often as possible, to work
around this problem.  Due to the MPD 0.14 code freeze, we should not
optimize the buffering code now.

We want to remove gcc.h eventually. This takes care of all the G_GNUC_PRINTF
macros.

The client may provide the names of idle events as arguments to the
"idle" command to inform MPD that it is only interested in these
events.

Return bool instead of int.

After a partial write, chances are vanishing that another write() will
succeed.  Don't try immediately.

Another custom data structore converted to GLib.

Replace a custom data structure with a GLib one.

The list cache aims to save memory allocations, and complicates the
code a bit.  We should rather use GLib slices later, which are easy to
use.

Eliminate CamelCase in all public and static functions.

client->permission is a bit set, and should be unsigned.