Compliant/4.0.x

The main idea of this PR is to have a New Slider project compliant with 4.0.x version of eXo Platform, thus with the new Javascript Module Definition of GateIn.
Some additional features where added in order to automate/facilitate the built of the project:
1. Added ```Maven``` nature to project and decoupled it in two modules:
* `artifacts`: which holds the xml serialized export of the _NewsFolder.xml_ node and the application template (_ NewsSliderCLVTemplate.gtmpl _). *_Note that this template is now imported automatically for first startup with the _ApplicationTemplateManagerService_*.
* `resources`: which stands for an extension along with `activator` and `webapp` modules (straightforward structure of a GateIn extension) and that holds the Skin and JS modules declaration.
2. The _NewsSliderCLVTemplate.gtmpl_ was broken into 2 chunks. The static content is left in it but all dynamic code was moved out to a JavaScript file `news-slider.js`.
3. Replaced the `jQuery Easing` plugin with non minified version to delegate minification to the portal (used for debug purposes). This plugin was also wrapped inside a self execution block with jQuery dependency.

*The current maven project was tagged with a 2.0.0 version (to mention it as a first onward release). I can create a PR to add maven nature to the base project and tag it with the 1.0.0 ref and have rallied versions.*