Update ng-ckeditor.src.js

Exposes the editor being ready to broader application environment, allowing things like:

HTML
-----
```
<div ng-controller="EditingController">
    <div ng-cloak ng-hide="isReady" class="highlight">
	Initialising ...
    </div>
    <div ng-cloak ng-show="isReady">
        The Textarea with ckeditor directive etc here
    </div>
</div>
```
APPLICATION
-----------
```
var editingController = [ "$scope", function( scope ) {
    scope.editorOptions = {
        config etc here
    };

    scope.$on( "ckeditor.ready", function( event ) {
        scope.isReady = true;
    });
}];

AdvancedEditor.controller("EditingController", editingController);
```
Allows us to hide everything until all rendered - useful when ckeditor needs to auto resize to fit placement space and when we add extra controls (external to the editor) that depend upon it etc ...