android: implement GLAdapter

- remove the Gdx implementation

vtm-android/src/org/oscim/android/AndroidMapView.java

@@ -16,6 +16,7 @@
 package org.oscim.android;
 
 import org.oscim.android.canvas.AndroidGraphics;
+import org.oscim.android.gl.AndroidGL;
 import org.oscim.android.input.AndroidMotionEvent;
 import org.oscim.backend.AssetAdapter;
 import org.oscim.backend.CanvasAdapter;
@@ -29,8 +30,6 @@ import android.util.AttributeSet;
 import android.util.DisplayMetrics;
 import android.widget.RelativeLayout;
 
-import com.badlogic.gdx.backends.android.AndroidGL20;
-
 /**
  * A MapView shows a map on the display of the device. It handles all user input
  * and touch gestures to move and zoom the map.
@@ -63,7 +62,7 @@ public class AndroidMapView extends RelativeLayout {
 		//System.loadLibrary("tessellate");
 
 		CanvasAdapter.g = AndroidGraphics.INSTANCE;
-		GLAdapter.g = new AndroidGL20();
+		GLAdapter.g = new AndroidGL();
 		Log.logger = new AndroidLog();
 	}