Refactor: Repo #*Many methods now return an EventEmitter object 'StreamingRepoOp'.  This objected allows the caller to attach event handlers to 'data', 'error', 'cancelled' and 'done' events. It exposes #cancel and #exec methods for executing and cancelling the operation.
bug fix; updated delete example;
Bug fix for StreamingRepoOp execution capture
added demultiplexing mechanism for metadata lookups
Repo #*Many operations now support callback pattern and start streaming op immediately;  cancel functional; updated examples
Expanded event emit data so that all events emit in the err, res arity, supplying Webflow responses where appropriate.  Done always emits OK, even if some items resulted in errors, it is the expectation that the client will handle those situations when handling DATA events.