[AD] Addons directory cleanup

[Michał Cichoń <michcic@xxxxxxxxxx>]

Hello,

I have two propositions with regard to add-on directory:
 - remove unused directories: iio, kcm_audio
 - reflect main directory structure in add-on directories

While first one does not need the comment, second should be explained
a little bit.
Maybe by example. Let's take a look at acodec add-on directory tree:

allegro5\
allegro5\internal\
allegro5\internal\aintern_acodec_cfg.h.cmake
allegro5\allegro_acodec.h
CMakeLists.txt
acodec.h
wav.c
ogg.c
modaudio.c
flac.c
acodec.c

Now, while preparing monolith build and using Allegro inside other
project I hit a problem of polluted include list. I can actually write
# include "wav.c" and whole wav.c source will be included (!). To
prevent such situation in the future I propose to reflect Allegro
directory tree inside add-ons:

include\ - public headers
src\ - source code
misc\ - support/additional files which are not a part of the add-on
directly (nshader.cpp for example in primitive add-on)

So, complete acodec library with new layout will look like that:

include\allegro5\
include\allegro5\internal\
include\allegro5\internal\aintern_acodec_cfg.h.cmake
include\allegro5\allegro_acodec.h
src\acodec.h
src\wav.c
src\ogg.c
src\modaudio.c
src\flac.c
src\acodec.c
CMakeLists.txt

This way I could just point to 'include' directory, which is not
polluted with C files. cmake files are harmless.

I'm interested in your approval. Before I do such modification.

-- 
thedmd, Michał Cichoń
Artifex Mundi
michcic@xxxxxxxxxx
http://www.artifexmundi.com