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/media/libeffects/testlibs/Android.mk_ b/media/libeffects/testlibs/Android.mk_
index 9ba71ed..98d477b 100644
--- a/media/libeffects/testlibs/Android.mk_
+++ b/media/libeffects/testlibs/Android.mk_
@@ -25,7 +25,7 @@
 LOCAL_C_INCLUDES := \
 	$(call include-path-for, graphics corecg)
 
-LOCAL_PRELINK_MODULE := false
+LOCAL_MODULE_TAGS := optional
 
 include $(BUILD_SHARED_LIBRARY)
 
@@ -60,7 +60,7 @@
 LOCAL_C_INCLUDES := \
 	$(call include-path-for, graphics corecg)
 
-LOCAL_PRELINK_MODULE := false
+LOCAL_MODULE_TAGS := optional
 
 include $(BUILD_SHARED_LIBRARY)