Added 'Fail' method to RunnableComponent which allows component to move from Running to Failed state. Added PollingComponent a timer based runnable component More tests Added FailPromise a thin class to wrap exceptions Fixed error handling in SuccessPromise classes.

using System;

namespace Implab {
    public interface ITaskController: IProgressHandler, ICancellable {
        bool IsCancelled {
            get;
        }

        event EventHandler Cancelled;
    }
}