http://xkcd.com/292/

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.

Without a music_directory, MPD is an excellent streaming client.

Don't include conf.h in database.c.

Don't return a writable pointer.

Renamed functions, types, variables.

Make db_load(), db_save() and db_check() return bool instead of int.

For updating the database, directory_update_init() should be called
explicitly.

Start the daemon after --create-db.  This makes --create-db a flag
which discards the old database and starts with a fresh one.

Make the event_pipe (formerly main_notify) send/receive a set of
events, with a callback for each one.

The default event PIPE_EVENT_SIGNAL does not have a callback.  It
is still there for waking up the main thread, when it is waiting for
the player thread.

Continuing the previous patch.

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.

Only include headers which are really needed.  os_compat.h aimed to
make MPD easily portable, but was never actually made portable.

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

Rename variables and functions.

Remove duplicated code from MPD.

Again, GLib's version is more robust than ours.

Since the return value cannot be -1 anymore, we can make it unsigned.

The documentation for directory_update_init() was incorrect: a job ID
must be positive, not non-negative.  If the update queue is full and
no job was created, it makes more sense to return 0 instead of -1,
because it is more consistent with the return value of isUpdatingDB().

If the user requests database update during startup, call
directory_update_init().  This should be changed to fully asynchronous
update later.

For this to work, main_notify has to be initialized before db_init().

Search'n'replace typo..

Remove clutter from directory.c.  Everything which saves or loads
to/from the hard disk goes to directory_save.c, and code which sends
directory information to the client is moved into directory_print.c.

Use sizeof(buffer) instead.

Removed a superfluous closure.

For the root directory, let's set path to an empty string.  This saves
a few checks.

CamelCase is ugly, rename the functions.

Yet another CamelCase removal patch.

The same can be achieved with directory_print(db_get_directory()).

Taming the directory.c monster, part II: move the database management
stuff to database.  directory.c should only contain code which works
on directory objects.

The function isRootDirectory() is tiny and can be converted to an
inline function.  Don't allow name==NULL.

CamelCase is ugly...  rename all functions.

Again, a data type which can be forward-declared.

The struct can be forward-declared by other headers, which relaxes the
header dependencies.

exploreDirectory() duplicates some code in updateDirectory().  Merge
both functions, and use directory_is_empty() to determine whether
update or explore mode should be used.

directory_is_empty() is a tiny inline function which determine if a
directory has any child objects (sub directories or songs).

The source directory.c mixes several libraries: directory object
management, database management and database update, resulting in a
1000+ line monster.  Move the whole database update code to update.c.

oops :x