React to UsePerRequestServices

Okay so it looks like ConfigureServices gets called by hosting regardless of which overload gets called, so shouldn't these methods have the same name?

I added the following test just to verify that having a ConfigureServices and then passing in a Action(IServiceCollection) add both sets of services.  Although it does mess up the options (the ConfigureServices options get ignored, so I need to investigate that behavior more)

```
        public void ConfigureServicesUseServices(IServiceCollection services)
        {
            services.Configure<FakeOptions>(o => o.Configured = true);
            services.AddTransient<IFakeService, FakeService>();
        }

        public void Configure(IApplicationBuilder builder)
        {
            builder.UsePerRequestServices(services =>
            {
                services.AddTransient<FakeService>();
                services.Configure<FakeOptions>(o => o.Message = "Configured");
            });
        }

        [Fact]
        public void StartupClassWithConfigureServicesAndUseServicesAddsBothToServices()
        {
            var serviceCollection = new ServiceCollection();
            serviceCollection.Add(HostingServices.GetDefaultServices());
            var services = serviceCollection.BuildServiceProvider();
            var manager = services.GetService<IStartupManager>();

            var startup = manager.LoadStartup("Microsoft.AspNet.Hosting.Tests", "UseServices");

            var app = new ApplicationBuilder(services);

            startup.Invoke(app);

            Assert.NotNull(app.ApplicationServices.GetService<FakeService>());
            Assert.NotNull(app.ApplicationServices.GetService<IFakeService>());

            var options = app.ApplicationServices.GetService<IOptions<FakeOptions>>().Options;
            Assert.NotNull(options);
            Assert.Equal("Configured", options.Message);
            Assert.False(options.Configured); // REVIEW: why doesn't the ConfigureServices ConfigureOptions get run?
        }