This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

Replaces g_uri_parse_scheme().

Remove GLib dependency from some headers.

Let gcc optimize a little bit more.

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.

Added the uri_remove_auth() library function which strips username
and password from a HTTP URI, and use it in song_print_url().  This
allows you to add HTTP URIs to the playlist including secret username
and password, without disclosing it to all MPD clients.

"ls" is a bad name for a library which parses URIs.  We'll move the
rest of the "ls" library later.

Added audio_format_parse() in a separate library, with a modern
interface: return a GError instead of logging errors.  This allows the
caller to deal with the error.

In generic PCM functions allowing all sample formats, pass a void
pointer instead of a char pointer.

Moved the software mixing code (used by crossfading) to a separate
library.

Don't use libc's rand() function, because it is slow.  Our own trivial
linear congruential generator is good enough for dithering.

redirect_stdin() is a daemonization function, and disconnecting from
the standard input is always a good idea for MPD.

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