Move extension methods to builder namespace and fix sample

samples/KWebStartup/Startup.cs

@@ -16,6 +16,7 @@
 // permissions and limitations under the License.
 
 using Microsoft.AspNet;
+using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Http;
 
 namespace KWebStartup

src/Microsoft.AspNet.RequestContainer/ContainerExtensions.cs

@@ -23,9 +23,8 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.DependencyInjection;
 using Microsoft.AspNet.DependencyInjection.Fallback;
 using Microsoft.AspNet.RequestContainer;
-using Microsoft.AspNet.Builder;
 
-namespace Microsoft.AspNet
+namespace Microsoft.AspNet.Builder
 {
     public static class ContainerExtensions
     {