Fix #3102 - Add an AddMvcOptions to builders

This makes it easier/possible for any third party code that extends
IMvcBuilder to set options.

NuGet.config

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
     <add key="AspNetVNext" value="https://www.myget.org/F/aspnetcidev/api/v3/index.json" />

src/Microsoft.AspNet.Mvc.Core/DependencyInjection/MvcCoreMvcBuilderExtensions.cs

@@ -16,6 +16,20 @@ namespace Microsoft.Framework.DependencyInjection
     /// </summary>
     public static class MvcCoreMvcBuilderExtensions
     {
+        /// <summary>
+        /// Registers an action to configure <see cref="MvcOptions"/>.
+        /// </summary>
+        /// <param name="builder">The <see cref="IMvcBuilder"/>.</param>
+        /// <param name="setupAction">An <see cref="Action{MvcOptions}"/>.</param>
+        /// <returns>The <see cref="IMvcBuilder"/>.</returns>
+        public static IMvcBuilder AddMvcOptions(
+            [NotNull] this IMvcBuilder builder,
+            [NotNull] Action<MvcOptions> setupAction)
+        {
+            builder.Services.Configure<MvcOptions>(setupAction);
+            return builder;
+        }
+
         public static IMvcBuilder AddFormatterMappings(
             [NotNull] this IMvcBuilder builder,
             [NotNull] Action<FormatterMappings> setupAction)

src/Microsoft.AspNet.Mvc.Core/DependencyInjection/MvcCoreMvcCoreBuilderExtensions.cs

@@ -16,6 +16,20 @@ namespace Microsoft.Framework.DependencyInjection
 {
     public static class MvcCoreMvcCoreBuilderExtensions
     {
+        /// <summary>
+        /// Registers an action to configure <see cref="MvcOptions"/>.
+        /// </summary>
+        /// <param name="builder">The <see cref="IMvcCoreBuilder"/>.</param>
+        /// <param name="setupAction">An <see cref="Action{MvcOptions}"/>.</param>
+        /// <returns>The <see cref="IMvcCoreBuilder"/>.</returns>
+        public static IMvcCoreBuilder AddMvcOptions(
+            [NotNull] this IMvcCoreBuilder builder,
+            [NotNull] Action<MvcOptions> setupAction)
+        {
+            builder.Services.Configure<MvcOptions>(setupAction);
+            return builder;
+        }
+
         public static IMvcCoreBuilder AddFormatterMappings(this IMvcCoreBuilder builder)
         {
             AddFormatterMappingsServices(builder.Services);