Fatal bug fix

There has been some issues with the use of 'end' event when doing the
https requests to retrieve the packages.json.
Fix for libraries.json download

The issue was not end/close, but related to HTTP redirect action from
Github.com.
Added support for project.json (ASP.NET vNext)

Tried to fix issue with from file format on bin\upm (was UTF-8 with
signature).
Added support for a custom "libraries" section within the project.json
file.