Converted part of the solution to C# 6
Replace String.Format calls with string interpolation
Updated the view project to C# 6
Use the VS 2015 Roslyn compiler in  the build scripts
Install Roslyn as NuGet package
Merge pull request #139 from flagbug/csharp6

C# 6
Use the nameof keyword instead of hardcoded strings
Use Rx directly to handle the library updates
Set IsUpdating to false when unsubscribing
Updated MahApps.Metro to the latest alpha version
Added the xUnit Visual Studio runner via NuGet
Added some argument checks