Implementation of reference counters for wrapping. We use some
reflection tricks to expose the NotesBase.GetCppObj method, which really
just returns the long that is the pointer for the handle in the C API.
It would be a really useful way of identifying your Notes objects, which
is probably why it isn't public. :-/

Signed-off-by: Nathan T Freeman <nathan.freeman@redpilldevelopment.com>