Converted tests to be async await.

- There were a few tests that seemed convertible but did not work.  Will revisit the todo's.
add AsyncManualResetEvent to Functional Tests

Conflicts:
	tests/Microsoft.AspNet.SignalR.FunctionalTests/Client/KeepAliveFacts.cs
	tests/Microsoft.AspNet.SignalR.FunctionalTests/Server/Connections/ConnectionFacts.cs
	tests/Microsoft.AspNet.SignalR.Tests.Common/Microsoft.AspNet.SignalR.Tests.Common.csproj
change Thread.Sleep to Task.Delay

Conflicts:
	tests/Microsoft.AspNet.SignalR.FunctionalTests/Server/Connections/ConnectionFacts.cs