Since we switched from autotools to Meson in commit
94592c14, we don't need to include
`config.h` early to properly enable large file support.  Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.

This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.

Fixes build problems with mingw32.

Don't allocate each replay_gain_info object on the heap.  Those
objects who held a pointer now store a full replay_gain_info object.
This reduces the number of allocations and heap fragmentation.

The previous patch not only moved code, it also changed the check.
Negative gain values seem to be valid after all, there just was the
"magic" value 0.0 which means "not available".  This patch changes the
"magic" value to "INFINITY", and uses the C99 function isinf() to
check.  It might have been a better idea to use "NAN", but the "NAN"
macro is a GNU extension.

Moved (and renamed) the function calc_replay_gain_scale() to
replay_gain_info.c.

This function determines whether replay gain data is available.

The replay_gain_state struct holds the precalculated scale factor,
which is removed from struct replay_gain_info.

The new command "replay_gain_mode" allows the user to switch the
replay gain mode on-the-fly.  No more mpd.conf editing.

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.

Having an array instead of individual variables allows the use of the
replay_gain_mode enum as an array index.

Prefer C enums over CPP macros.

Renamed functions and variables.

No CamelCase file names.

"LOG_H" is a macro which is also used by ffmpeg/log.h.  This is
ffmpeg's fault, because short macros should be reserved for
applications, but since it's always a good idea to choose prefixed
macro names, even for applications, we are going to do that in MPD.

Get rid of CamelCase, and don't use a typedef, so we can
forward-declare it, and unclutter the include dependencies.

We want to expose the AudioFormat structure to plugins; remove some
clutter by moving its declaration to a separate header file.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7342 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@5834 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Add -Wmissing-prototypes if compiling with gcc
Static where possible

git-svn-id: https://svn.musicpd.org/mpd/trunk@4657 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@4445 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Indent the entire tree, hopefully we can keep
it indented.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4410 09075e82-0dd4-0310-85a5-a0d7c8717e4f