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.Diagnostics {
    public interface ILogWriter<in TEvent> {
        void Write(LogEventArgs args, TEvent entry);
    }
}