Proxy handler API wiki page updated

# Tom Van Cutsem (12 years ago)

At the May TC39 meeting it was decided to accompany the Proxy API with a proxy handler API that helps developers write better, more consistent Proxy abstractions.

Allen and I ironed out the details, and I have updated the appropriate wiki page with a proposed design (a minimal class hierarchy that covers what we think are the important use cases).

We welcome feedback from the list, so that we can take it into account before presenting the updated design at a next TC39 meeting.

harmony:virtual_object_api