[wsrp-wsia] Create Issue: destroyEntities() & refHandles

Topic:  interface
Class:  Technical
Title:  destroyEntities() & refHandles
Document Section: 5.2
Description:
At the F2F we separated releasedHandles() into 2 operations, one of which
is destroyEntities(). We also began the exploration of what the signatures
would look like with a unified refHandle that encode both entityHandle and
sessionID. What semantics do we want to define for a refHandle being passed
to destroyEntities()? What are the semantics for destroying entities that
have active sessions on them?