WIP: Service Mocks

This is a WIP PR for adding support for desktop/unit testing mocks for common cordova services.

The idea is you can call cordova plugin services even if you are testing in a non-device setting where cordova doesn't exist. The calls will still work, or at the very least print a console warning.

Then, you can "mock" the services for testing, like taking a photo:

```javascript
// Set up mock
$cordovaCamera.whenGetPicture('profile', 'img/test/face.png');

// In controller or somewhere else:
$cordovaCamera.getPicture('profile').then(function(imageData) {
});
```