Add CancellationToken support to Async methods

[Kim-SSi]

No description provided.

[Kim-SSi]

The reason for this change is that I am using @implements IDisposable in components and want to be able to cancel the Async calls.

    private readonly CancellationTokenSource TokenSource = newCancellationTokenSource();

    public void Dispose()
    {
        TokenSource.Cancel();
    }

[chrissainty]

Apologies for the delay getting to this @Kim-SSi. Everything looks good here, I'll get it merged.