Previously you could just use the package manager console inside of VS. But now all the examples are using command line tools outside of VS. Like this:
http://docs.asp.net/projects/mvc/en/latest/tutorials/mvc-with-entity-framework.html
What is the reason for this ?
The NuGet commands will eventually work (see issue #978), but they need some features to be implemented by the NuGet and Web Tools teams first.