Message Handler; Can now receive 'NoContent=True' URL parameter to return an HTTP 'No Content' header

By default, when the Message Handler receives a message from a Web Browser, e.g., typed in as a URL, it returns a summary of the message, its parameters and return values.

When providing a link on an HTML page though, it may be desirable to simply remain on the same page without showing any summary of the request.

A "NoContent" parameters can now be appended to the URL to achieve this, e.g.:

http://localhost:5000/APPLICATIONSHORTCUT.FORMSHOW?form=clients&id=C10000&nocontent=true

This will cause the Message Handler to return an HTTP 204 No Content message to the Web Browser. The Web Browser will then remain on the same page.