[c#] No syntax colors in C# for usings out of namespace

[aeschli]

From @vbfox on December 1, 2015 9:8

In the following code :

using System.Linq;

namespace MyNamespaceIsFoo
{
    using System;

    public class SearchKey
    {
    }
}

using System get colored correctly but using System.Linq isn't.

Copied from original issue: microsoft/vscode#848

[aeschli]

Same problem in Atom

[damieng]

Is now fixed I think through a number of commits;