Disabling hosting startup

- VS injects a bad version of AppInsights because it doesn't
check the shared framework version in use. Since we constantly
are on the bleeding edge, we get out of sync frequently. This
change disables them from running.

samples/ChatSample/Program.cs

@@ -12,6 +12,7 @@ namespace ChatSample
         public static void Main(string[] args)
         {
             var host = new WebHostBuilder()
+                .UseSetting(WebHostDefaults.PreventHostingStartupKey, "true")
                 .ConfigureLogging((context, factory) =>
                 {
                     factory.UseConfiguration(context.Configuration.GetSection("Logging"));

samples/SocialWeather/Program.cs

@@ -12,6 +12,7 @@ namespace SocialWeather
         public static void Main(string[] args)
         {
             var host = new WebHostBuilder()
+                .UseSetting(WebHostDefaults.PreventHostingStartupKey, "true")
                 .ConfigureLogging(factory =>
                 {
                     factory.AddConsole();

samples/SocketsSample/Program.cs

@@ -18,6 +18,7 @@ namespace SocketsSample
 
             var host = new WebHostBuilder()
                 .UseConfiguration(config)
+                .UseSetting(WebHostDefaults.PreventHostingStartupKey, "true")
                 .ConfigureLogging(factory =>
                 {
                     factory.AddConsole();