[Package] Implementation of Tizen Package API

This branch includes a fully functional implementation of Tizen Package API. 

API specification can be found at:
https://developer.tizen.org/dev-guide/2.2.0/org.tizen.web.device.apireference/tizen/package.html

BUG=XWALK-443
```
  } else if (m[asyncCallbacks.key] === asyncCallbacks.infoEvent &&
                exports.changeListener != null) {
```
so that you can save indent and avoid long `if` block below