Move C++ API over to function tables rather than linking libRS directly.

Change-Id: I7841df768d5bd10fa941b3655673fd73496a8137
diff --git a/cpp/Android.mk b/cpp/Android.mk
index 145f487..689b2fa 100644
--- a/cpp/Android.mk
+++ b/cpp/Android.mk
@@ -28,7 +28,8 @@
 	libz \
 	libcutils \
 	libutils \
-	liblog
+	liblog \
+	libdl
 
 LOCAL_MODULE:= libRScpp