Does these file structural change official in asp.net core 1.1 compared to asp.net core 1.0?

I have seen lot of tutorial and articles online regarding .NET CORE 1.0(because there are no much detail articles on version 1.1)

Apart for many advantages there were lot of changes in file structure.

But when I created application in .NET CORE 1.1 and ASP.NET MVC 1.1. I realized that there are lot of changes in files structures compared to .NET CORE 1.0 file structure(Few files are missing and few folders are missing)

Files missing in .NET CORE 1.1 from .NET CORE 1.0:

1. project.json
2. global.json
3. package.json

Question 1: In few articles I read project.json is replaced with new .csproj file. But I think package.json and project.json are combined as .csproj file because I can see npm references in .csproj file. Am I right?

Question 2: I cant find the reference of sdk components "Microsoft.NETCORE.App" in any file which will be usually defined in global.json file in .NET CORE 1.0. Now in .NET CORE 1.1 I can find global.json file. Then where is the reference is mentioned? I think without mentioning a reference the sdk package will not load.

Folders missing in .NET CORE 1.1 from .NET CORE 1.0:

1. Src folder
2. Solution files folder

Question 3: Are these folders officially removed from the projects file structure?

Question 4: Are these folders and files optional? Personally I feel very good and less confused with this files not being there.