Fix references to other exported types in typedefs

[jasongin]

Fixes: #267

• Omit the namespace when referencing other exported types in a module. Types tagged with [JSExport] are un-namesapced in JS, even if they are namespaced in .NET.
• Use the "export name" when referencing other exported types in a module. That is the optional name override in the [JSExport("name")] attribute. It defaults to the regular type name.
• Add a reference to another exported, namespaced type in the test Module.cs file. The generated type-definitions for those types will be checked by the TS compiler as part of the project test cases.