misc: fix stuff up to make SDL example work again

it still behaves weirdly, should probably find some
other example since I don't trust my own code.

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

@@ -390,5 +390,7 @@ public class Activity extends Context implements Window.Callback {
 		finish();
 	}
 
+	public void setIntent(Intent newIntent) {}
+
 	public void unregisterReceiver(BroadcastReceiver receiver) {}
 }

src/api-impl/android/content/Context.java

@@ -443,4 +443,8 @@ public class Context extends Object {
 	public void unbindService(ServiceConnection serviceConnection) {}
 
 	public void unregisterReceiver(BroadcastReceiver receiver) {}
+
+	public Context createPackageContext(String dummy, int dummy2) {
+		return this; // FIXME?
+	}
 }

src/api-impl/android/content/res/AssetManager.java

@@ -464,11 +464,14 @@ public final class AssetManager {
 				throw new RuntimeException("Assetmanager has been closed");
 			}
 			asset = openAsset(fileName, 0);
+			if (asset < 0)
+				throw new FileNotFoundException("Asset file: " + fileName + ", errno: " + asset);
+
 			FileDescriptor fd = new FileDescriptor();
 			fd.setInt$(asset);
 			ParcelFileDescriptor pfd = new ParcelFileDescriptor(fd);
 			if (pfd != null) {
-				AssetFileDescriptor afd = new AssetFileDescriptor(pfd, mOffsets[0], mOffsets[1]);
+				AssetFileDescriptor afd = new AssetFileDescriptor(pfd, 0, getAssetLength(asset));
 				afd.fileName = "/assets/" + fileName;
 				return afd;
 			}
@@ -860,7 +863,9 @@ public final class AssetManager {
 	/*package*/ /*native*/ final String getResourceName(int resid) {
 		return tableBlockSearch(resid).pickOne().getName();
 	}
-	/*package*/ native final String getResourcePackageName(int resid);
+	/*package*/ /*native*/ final String getResourcePackageName(int resid) {
+		return tableBlockSearch(resid).pickOne().getPackageName();
+	}
 	/*package*/ /*native*/ final String getResourceTypeName(int resid) {
 		return tableBlockSearch(resid).pickOne().getTypeName();
 	}

src/api-impl/android/hardware/SensorManager.java

@@ -31,4 +31,8 @@ public class SensorManager {
 				return false;
 		}
 	}
+
+	public void unregisterListener(final SensorEventListener listener, Sensor sensor) {
+		System.out.println("STUB: andoroid.hw.SensorManager.unregisterListener");
+	}
 }

src/api-impl/android/provider/Settings.java

@@ -10,6 +10,8 @@ public class Settings {
 			switch (key) {
 				case "android_id":
 					return "_totally_an_androidID"; // TODO: is this a good ID? :P
+				case "advertising_id":
+					return "";
 				default:
 					java.lang.System.out.println("!!!! Settings$Secure.getString: unknown key: >" + key + "<");
 					return "NOTICEME";