Don't compile the sources of disabled output plugins at all.

Again, no CamelCase in the directory name.

The last bit of CamelCase in audio_format.h.  Additionally, rename a
bunch of local variables.

Having an array with disabled entries sucks.  Removed that
DISABLED_SHOUT_ENCODER_PLUGIN macro, and fill the plugin list only
with plugins which are actually enabled.  This should be done for all
plugin types.

Do full C99 integer type conversion in all modules which were not
touched by Eric's merged patch.

The inline function audio_format_sample_size() calculates how many
bytes each sample consumes.  This function already takes into account
that 24 bit samples are 4 bytes long, not 3.

Since the buffer size is known at compile time, we can save an
indirection by declaring it as a char array instead of a pointer.
That saves an extra allocation, and we can calculate with the
compile-time constant sizeof(data) instead of the attribute "max_len".

Declare both shout plugins "const", since they will never change, once
initialized at compile time.

Don't typedef the structs at all.  It is easier to forward-declare
this way.

Don't typedef methods.  They are used exactly once, a few lines below.

[mk: moved this patch after "Refactor and cleanup of shout Ogg and MP3
audio outputs".  The original commit message follows, although it is
outdated:]

Creation of shout_mp3 audio output plugin. Basically I just copied the
existing shout plugin and replaced ogg with lame. Uses lame for mp3
encoding. Next step is to pull common functionality out of each shout
plugin and share it between them.

Configuration options for "shout_mp3" are the same as for "shout".