Made other overload of LongPollingTransport.Send non virtual.

#1292
Signed connection ids.
- Added API to Protect/Unprotect data.
- Default implementation uses DPAPI.
- Updated tests.
- Fixed issues in .NET client where connection ids were not encoded.
- Added ASP.NET specific ProtectedData that uses the MachineKey

#1305
Made scope in DefaultProtectedData configurable.
- Default is per User.
Made MachineKeyProtectedData40 a static class.

#1305
Changed Transport.ConnectionId to be settable so that it always has the unprotected version.
- Fixed encoding of Abort request in HttpBasedTransport.

#1305
Send connection token and connection id back to client
- Connection.ConnectionId doesn't change client side.
- Updated the .NET client and JS client
- Updated the protocol version

#1305
Fixed tests for new connectionToken semantics.
Made some changes per review feedback.
- Handle null connectionId after unprotect calls.
- Use singleton UTF8Encoding class.

#1305
Prefix signals to avoid collisions and security issues.
- Prefix all signals with a unique prefix.
- Changed various apis to IE<T> to IList<T>
- Updated tests.

#1320
Fixed security test.
Changes per review.
Updated RootNamespace of client projects to match AssemblyName

This ensures that the resources all have the correct logical name.
Added copyright to files.
Made MemoryHostRun work again.
Renamed RouteExtensions to SignalRRouteExtensions.
Change argument to params array on IHubConnectionContext.
Change .NET Client uses of arrays to IList.

#1288
End connection as soon as it's marked as not alive.
Ensure build works on paths with space eq: C:\My Projects\SignalR