TlbImp: Suppress types from being imported


With the new version we are able to map all references to the local IStream definition to System.Runtime.InteropServices.ComTypes.IStream.
Unfortunately the now unreferenced local IStream definition, as well as ISequentialStream, _ULARGE_INTEGER etc. are still part of the Interop.
As it is very annoying and confusing have multiple unsused IStream or other type definitions around it would be a nice feature to be able to suppress some types from going into the Interop.