Standalone Fluent ModelMetadata configuration registration

[AlexBar]

Added ability to use only Fluent ModelMetadata configuration without bootstrapping features of MvcExtensions.

Usage (example with Autofac):

// Global.asax.cs
protected void Application_Start()
{
     AreaRegistration.RegisterAllAreas();

     RegisterGlobalFilters(GlobalFilters.Filters);
     RegisterRoutes(RouteTable.Routes);

     ContainerBuilder builder = new ContainerBuilder();

     var current = ModelMetadataRegistrar.Current;
     current.RegisterMetadataTypes(
                (serviceType, implType) => builder.RegisterType(implType).As(serviceType).InstancePerDependency(),
                (serviceType, implType) => builder.RegisterType(implType).As(serviceType).SingleInstance());

     DependencyResolver.SetResolver(new AutofacDependencyResolver(builder.Build()));

     current.RegisterMetadataProviders(DependencyResolver.Current);
}

[hazzik]

I suppose that it would be greater if user would register all the metadata configuration by himself. So we can waste the RegisterMetadataTypes method as useless abstraction on IoC container.

[AlexBar]

ok, removed it

[AlexBar]

the changes are integrated into pull request #5 - https://github.com/MvcExtensions/Core/pull/5