title: Don't get updates on realm models work with RecyclerView/DataBinding
body: <p>While implementing a solution based on Realm Mobile Database, RecyclerView and DataBinding I am stuck in receiving a change notification from an edittext view (within recyclerview) that is bound to a realm model. I tried it with RxBinding (my favourite) but without success - when it came to item.setName()... It crashed.</p>
  
  <pre><code>final int row = vh.getAdapterPosition();
      final android.widget.EditText editText = (EditText)vh.itemView.findViewById(R.id.firstLine);
      Subscription editTextSub =
              RxTextView.textChanges(editText)
                      .subscribe(new Action1&lt;CharSequence&gt;() {
                          @Override
                          public void call(CharSequence charSequence) {
                              if (row != RecyclerView.NO_POSITION) {
                                  CrngyMaster item = (CrngyMaster) getItem(row);
                                  item.setName(charSequence.toString());
                              }
                          }
                      });
      // Make sure to unsubscribe the subscription
  </code></pre>
  
  <p>I changed the code to:</p>
  
  <pre><code>Subscription editTextSub =
              RxTextView.textChanges(editText)
                      .subscribe(new Action1&lt;CharSequence&gt;() {
                          @Override
                          public void call(CharSequence charSequence) {
                              int row = vh.getAdapterPosition();
                              if (row != RecyclerView.NO_POSITION) {
                                  CrngyMaster item = (CrngyMaster) getItem(row);
                                  String oldName = item.getName();
                                  String modified = charSequence.toString();
                                  if(Objects.equals(oldName, modified) == false) {
                                      CrngyMaster original = realm.where(CrngyMaster.class)
                                              .equalTo("mName", oldName)
                                              .findFirst();
  
                                      realm.beginTransaction();
                                      original.setName(modified);
                                      realm.commitTransaction();
                                  }
                              }
                          }
                      });
      // Make sure to unsubscribe the subscription
  </code></pre>
  
  <p>Now it's working, but:
  - is this the way it should be implemented? I will add primary keys but I want to prevent the items from being queried when the recyclerview is loaded. Is that possible? And the most important question: how do I unsubscribe?</p>