Updated scripts
Fixed potential memory leak in TransportHeartBeat.
- End the connection before removing it from the list in when the server command
  is received so that the subscription is cleaned up.

#1953
Added state tracking to transports.
- Added flags enum to show state transition history
  of a transport. This will make dumps much easier to
  analyze as we'll have more historical data.
Added more states for tracking.
Changed Initialized to None.
Use the closest mapping in the store when there's gaps.
- Pick the first element in the fragment bigger than
  requested mapping id when failing to find the element.
- Added unit tests.

#1973
Merge branch 'release' into dev

Conflicts:
	samples/Microsoft.AspNet.SignalR.Hosting.AspNet.Samples/Scripts/jquery.signalR.min.js
	samples/Microsoft.AspNet.SignalR.LoadTestHarness/Scripts/jquery.signalR.min.js