Official release of 4.0.0

While the **Web Forms** version of the **OnTopic Editor** is
considered obsolete, and is no longer supported by **Ignia**,
this version is provided to maintain minimum API compatibility
with the latest **OnTopic 4.0.0** release. This should help aid
implementors in upgrading to the **OnTopic-Web-MVC** or,
preferably, the **Ontopic-AspNetCore** version of the project.