gradle: update to 2.1 and android targetSdk 21

- add android-appcompat subproject

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

@@ -50,6 +50,7 @@ public class Compass {
 	private final SensorManager mSensorManager;
 	private final Sensor mSensor;
 
+	@SuppressWarnings("deprecation")
 	public Compass(Context context, Map map) {
 		mMap = map;
 		mSensorManager = (SensorManager) context

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

@@ -26,8 +26,8 @@ import org.oscim.map.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
-import android.os.Build;
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
 import android.view.GestureDetector;
@@ -89,6 +89,7 @@ public class MapView extends RelativeLayout {
 		mMap.pause(false);
 	}
 
+	@SuppressLint("ClickableViewAccessibility")
 	@Override
 	public boolean onTouchEvent(android.view.MotionEvent motionEvent) {