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/IAudioFlinger.h b/include/media/IAudioFlinger.h
index 589f7cd..75f3e71 100644
--- a/include/media/IAudioFlinger.h
+++ b/include/media/IAudioFlinger.h
@@ -27,7 +27,7 @@
 #include <media/IAudioTrack.h>
 #include <media/IAudioRecord.h>
 #include <media/IAudioFlingerClient.h>
-#include <media/EffectApi.h>
+#include <hardware/audio_effect.h>
 #include <media/IEffect.h>
 #include <media/IEffectClient.h>
 #include <utils/String8.h>