The root namespace variable for the JavaScript API

The JavaScript API of CKEditor, which contains the entire editor code, will be hold and be accessible through a unique and single namespace object. No other variables will be defined in the page running the editor. Now, we should think about the namespace variable name.

I've already started working on it, and the CKEDITOR name sounded good. It follows a tendency of having the root namespaces all uppercased, which definitely avoids variable collisions. I've also updated the documentation with it.

There could be other solutions for it, like a shorter name, like "CKE", but it looks quite strange for me.

Comments and criticisms are welcome.