New effect library API

Moved and renamed media/EffectApi.h to hardware/audio_effect.h
Modified the effect library API to expose a library info structure
containing an interface functions table.
Also removed enums for audio channels, audio format and devices
from effect API and use values from system/audio.h instead.

Modified effects factory to support new library interface format and
load libraries and efffects listed in audio_effects.conf file.
The file audio_effects.conf is first loaded from /vendor/etc and
then from /system/etc/audio_effects.conf if not found.

Modified existing effect libraries to implement the new library interface.

Change-Id: Ie52351e071b6d352fa2fbc06c3846686f8c45df9
diff --git a/include/media/EffectPresetReverbApi.h b/include/media/EffectPresetReverbApi.h
index a3f094c..e5b168a 100644
--- a/include/media/EffectPresetReverbApi.h
+++ b/include/media/EffectPresetReverbApi.h
@@ -17,7 +17,7 @@
 #ifndef ANDROID_EFFECTPRESETREVERBAPI_H_
 #define ANDROID_EFFECTPRESETREVERBAPI_H_
 
-#include <media/EffectApi.h>
+#include <hardware/audio_effect.h>
 
 #if __cplusplus
 extern "C" {