title: Nfc tag detected/lost listener
body: <p>I have been working on NFC MifareClassic card. I have read and written data on card.
  I want to show a notification to user when tag is detected that what I have,</p>
  
  <pre><code>    @Override
      protected void onNewIntent(Intent intent) {
      super.onNewIntent(intent);
  
      // 1) Parse the intent and get the action that triggered this intent
      String action = intent.getAction();
      if (NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)) {
          //  3) Get an instance of the TAG from the NfcAdapter
  
          Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
  
  
          AppController.getInstance().setTag(tagFromIntent);
  
      }
  }
  </code></pre>
  
  <p>but when tag is move away that is what I need. I want to show user that tag is no longer available. Is there any listener for it?</p>