[firefoxos] CB-3208 Added support for Firefox OS 

Modified so contacts gonna work on FFOS devices (privileged type is required).
manifest.webapp needs to be prepared 

```
{
  "launch_path": "/index.html",
  "version": "0.0.1",
  "name": "Mobile Spec",
  "pkgName": "io.cordova.mobilespec",
  "type": "privileged",
  "permissions": {
    "contacts": {
      "access": "readwrite",
      "description": "testing"
    }
  }
}
```