First try for implementation. Not building!!!
First attempt to make ICriteria.FutureAsync asynchronous
Parallel FutureAsync works
fixed unit test
DelayedEnumerator is an IAwaitableEnumarable now. FutureAsync returns an IAwaitableEnumarable that has an AsTask method.
Updateded API description
testing roundtrips for combined Futureasync and normal Future
Removed FutureAsync API method. Future offers all thats needed.

Users of old API will not notice any difference since
IAwaitableEnumerabe is IEnumerable. It's an expension, so old usage also
works.
Removed FutureAsync API method. Future offers all thats needed.

Users of old API will not notice any difference since
IAwaitableEnumerabe is IEnumerable. It's an expension, so old usage also
works.