ENYO-3708: sanitize Ares2 folder layout & prepare for minification

* JIRA: https://enyojs.atlassian.net/browse/ENYO-3708
* Tested on: OSX/Chrome, OSX/Safari
* New startup URL (startup with `-b` still working): http://localhost:9009/ide/
* New Preview URL (`/preview.html` instead of `/preview/index.html`
* New source code layout (see `CONTRIBUTE.md`)

```
source/*            Multi-Project View
├── enyo-editor     File Editor
│   ├── deimos      Drag-n-Drop Designer
│   └── phobos      Code Editor
├── harmonia        Access to Ares Server (ide.js) Services
│   └── services
├── preview         Preview Current Project
├── project-view    Single-Project View
└── utilities       As it says...
```

* ENYO-3708: move `source/services` as `source/harmonia/services`
* ENYO-3708: fix `phonegap` following layout change
* ENYO-3708: add missing `package.js`
* ENYO-3708: fix `preview` following layout change
* ENYO-3708: `phobos` & `deimos` as sub-feature of `enyo-editor`
* ENYO-3708, ENYO-2627: move Ares2 sub-features under source/ and assets/
* ENYO-3708, ENYO-2627: move Ares2 main source in the top folder
* ENYO-3708: Start consolidating assets in a single location

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>