Changed the project file to be able to be built using the msbuild from the command line. You'll still need the Roslyn preview installed in Visual Studio
Made a file to build the project from command line.
Also updated the pack cmd file to build the project and then pack it, only if the build succeeded.
  - Updated the AssemblyInfo.cs file with information about the package.
  - Updated the nuspec file to read information from the included assembly.