This involves a large amount of change in test scene setup code to allow test scenes to share shared modules
SetupScene is now an instance method that requires an instantiation of SceneHelpers, though other SceneHelpers methods are still static
May split these out into separate classes in the future.
The Path.GetDirectoryName call in Compiler.CompileFromDotNetText is unnecessary since AppDomain.CurrentDomain.BaseDirectory is always a directory.
Later path concatenation is already done by Path.Combine() which handles any trailing slash.
Removing Path.GetDirectoryName() will not affect the runtime but allows NUnit to work since it doesn't add a trailing slash to AppDomain.CurrentDomain.BaseDirectory.
