Updating Newtonsoft.Json to 6.0.6

We use Json.NET to parse `project.json` for ASP.NET 5 projects. They use Json.NET 6 and the main issue is that they include single-line comments in the json files which is not supported in 5.x
well, I don't really know why it's still failing to compile at this point. After removing that SDK, it complained about some VS2012 binary, after removing that, it's still failing to compile saying that there is a conflict between 4.5.0.0 and 6.0.0.0. I am not sure where it's getting 4.5.0.0 at all! I will take another look tomorrow