NLog.Web.AspNetCore 4.9

This version adds support for ASP.NET Core 3 and some nice renderers has been added and improved!

• #496 Support ASP.NET Core 3 (@snakefoot, @304NotModified)
• #491 Added example with ASP.NET Core 3 (@304NotModified)
• #477 Added ${aspnet-response-statuscode} - rendering response status code (@304NotModified, @ThomasArdal)
• #473 Added ${aspnet-request-headers} - rendering headers for ASP.NET and ASP.NET Core (@ThomasArdal)
• #472 ${aspnet-request-cookie} - Added Exclude option (@snakefoot)
• #465 ${aspnet-request-cookie} (without cookienames) will render all cookies (@304NotModified)
• #494 Added AddNLog with functor to create/initialize LogFactory for NLogLoggingProvider (@snakefoot)
• #483 AddNLog-methods for ILoggingBuilder (@snakefoot)