add initial support for fragments

Fragments are not added to the View hierarchy yet. Only the lifecycle
callbacks are implemented

src/api-impl/android/app/Fragment.java

@@ -1,5 +1,31 @@
 package android.app;
 
+import android.os.Bundle;
+
 public class Fragment {
-	
+
+	Activity activity;
+
+	public void onCreate(Bundle savedInstanceState) {
+	}
+
+	public void onStart() {
+	}
+
+	public void onResume() {
+	}
+
+	public void onPause() {
+	}
+
+	public void onStop() {
+	}
+
+	public void onDestroy() {
+	}
+
+	public Activity getActivity() {
+		return activity;
+	}
+
 }