Made IEventStore GetAllEvents async - first step
All GetEventsXX methods async.
SaveEvents and GetCurrentVersion now async.
More async.
More async.
Added async to platform code.
More async.
Sample async’ed - now, will it work?
Use of semaphore slim for locking in memory repository
SUse of semaphore slim for locking in memory event store
Async method executor, fixed up use of async when calling aggregate methods.