Demo application demonstrating issue with livesync of external files

Steps to reproduce

1. Clone the repo
2. Run tns run <platform>
3. Apply a change in app/demo.js - the change must be shown on device, however CLI does not upload anything.

NOTE: Te change should be visible in case demo.js is defined as external or even when the WebpackIgnore plugin is used. To test the later scenario, use the webpack.config_ignore.js file instead of the current webpack.config.js.