v1.27.0 JWT/id_token validation, misc bug fixes
Bug fixes:
- #652 Provide synchronous way of accessing application default credentials
- #729 ApplicationName property isn't validated
- #982 Fix generated code that uses MediaDownloader.Download(...)
- #1016, #1017 Add all missing support library XmlDoc
- #1022 Unregister CancellationToken registration in net45 LocalServerCodeReceiver
- #1025 Clarify .NET Core support in nupkg summary
New features: