Updated the Serilog.Sinks.ApplicationInsights to Azure based AI

Big changes were made by MS recently in , this is the update for the Serilog Sink to the latest version. They've moved AI over from Visual Studio Online as an integrated part of Azure (see http://go.microsoft.com/fwlink/?LinkId=506854) and as part of that, they refactored & opened up their API a bit, too (see http://blogs.msdn.com/b/visualstudioalm/archive/2014/09/04/application-insights-sdk-0-10-0-prerelease.aspx).

The previous version of this sink I created was built against the Visual Studio Online version of AI, which is now depricated.

Cheers,
-J