SignalR/SignalR — pull request #1570 by davidfowl (2013-02-22 09:24:48+00:00)
Title: Fix issue on .NET 4.0 where cancellation token is already disposed.

- Dispose the token only if it's not a result of ending an existing
connection.
- Dispose the token before ending the connection.
- Catch ObjectDisposedException in SafeRegister's DisposableAction.