BackgroundTasks: Use "Fire & Forget" approach when starting workers as…

[mjansenDatabay]

…ynchronously

This PR suggests making the start of asynchronous workers for background tasks really asynchronous to ensure a "Fire & Forget" approach. This is done by setting the "Response Timeout" to 0 and by adding a ignore_user_abort(true);) on the server-side (SOAP).