Preware: Implement Loading Screen

* Move menu scroller into an enyo.Panels
* Add loading screen panel
* Extend AppPanels.log to update the load info dialog
* Update this.log calls
* Update index.html to use cordova.js symlink
* Simplify index.html loading

Open-webOS-DCO-1.0-Signed-Off-By: Josh Palmer <jpalmerwatkins@me.com>