Automatic wrapper generation for object handles

Object handles wrappers provide constructor and access functions for object instances (in contrast with the static methods currently supported by Excel-DNA). It would be convenient to generate these wrappers.

One sample project with an implementation of object handles, with some specialized features like batch updating, can be found in the (Samples repository)[https://github.com/Excel-DNA/Samples/tree/master/ObjectHandles].

Using the RTD / IExcelObservable implementation to provide deterministic lifetime management has proven to be robust.

There are quite a number of design issue to resolve in implementing the wrapper generation. Among these:
- Identifying classes, constructors and methods/properties to generate wrappers for
- Details of the wrappers
- Update processing - INotifyPropertyChanged etc.

I'd welcome discussion and suggestions on what would be useful in this area.