If we're calling stop the OnError event shouldn't be raised.
Don't raise the error event when stopping the connection.
- Never throw an operation cancelled exception from the websocket handler,
just let it throw normally.
- Added functional test.
This still happens http://ci.signalr.net/viewLog.html?buildId=2420&tab=buildResultsDiv&buildTypeId=bt10&guest=1
Fix OnError getting called in wrong cases in .NET client.
- Fix other case where disconnect token is tripped and OnError is still called.