Support for linking with Google Play Services, also fixed Proguard config

project/proguard.cfg

@@ -1,4 +1,4 @@
--optimizationpasses 5
+-optimizationpasses 1
 -dontusemixedcaseclassnames
 -dontskipnonpubliclibraryclasses
 -dontpreverify
@@ -34,22 +34,3 @@
 -keep class * implements android.os.Parcelable {
   public static final android.os.Parcelable$Creator *;
 }
-
--keepclasseswithmembers class * {
-    native <methods>;
-}
-
--keep class com.<pkg>.AudioThread {
-    int initAudio(int, int, int, int);
-   int deinitAudio();
-   int pauseAudioPlayback();
-   int resumeAudioPlayback();
-   int fillBuffer();
-   int initAudioThread();
-   *** getBuffer();
-}
-
--keep class com.<pkg>.DemoRenderer {
-    int swapBuffers();
-   void showScreenKeyboard(java.lang.String, int);
-}