Make T4MVC work with ASP.NET 5

As David Ebbo (hey!) pointed out, R4MVC - a side project was started a long time ago, but was stalled due to (at the time) breaking changes in the Roslyn compiler.

Luckily, the project was revived, and R4MVC has just released it's first alpha build, with more changes coming soon.

While the project works somewhat differently, and isn't using t4 templates, the end result is the same, and we're working to achieve feature parity with T4MVC in the near future.

At this point, T4MVC is not designed to run on ASP.NET 5 projects, so I'm not surprised that it doesn't work.

A while back, a separate R4MVC project was started, using a Roslyn based approach. However, this was done at a time when there was no T4 support with ASP.NET 5, and that has now been revisited.

So it's possible that there is hope to get T4MVC running on there, but someone would need to invest the time to see how far it is from working.

I just took a tiny step and fixed the null ref that you hit (not yet released, you'll need to hand fix). However, I then hit a condition where it seems to hand altogether.

Anyway, this is not the place to fully investigate all issues, but if someone wants to take that on, we can discuss on https://github.com/T4MVC/T4MVC.