View service provider

Since 4.3 is emphasizing the use of service providers over bootstrap files I think it makes sense to have a **ViewServiceProvider** under app\Providers that can be used to bind any shared data, view composers, creators, etc. However, I'm not sure if this functionality has enough widespread use to actually warrant a new SP, nor am I sure about the naming (there already is an Illuminate ViewServiceProvider for that component so it could be confusing). It's also empty by default, though this may not be an issue as the AppServiceProvider is also empty.