slight adjustment

I added two more optional properties to the `addShareAction` method that can be passed by user instead of hard-coding:

* title
* showAsAction

Used like in MenuItem

```javascript
abextras.addShareAction({
  menu: e.menu,
  intent: intent,
  showAsAction: Ti.Android.SHOW_AS_ACTION_ALWAYS, // optional
  title: "Share Image" // optional
});
```