added Safe.DispatchEvent() a legacy equivalent for '?.Invoke()'...
added Safe.DispatchEvent() a legacy equivalent for '?.Invoke()'
added Safe.Dispose(IEnumerable)
added PromiseExtensions.CancellationPoint to add a cancellation point to the chain of promises
added IPromise<T> PromiseExtensions.Then<T>(this IPromise<T> that, Action<T> success) overloads
added PromiseExtensions.Error() overloads to handle a error or(and) a cancellation