Support multiple CDO handles from the same application

The PM needs to support a 'local-handle' addition to the CDO registry that permits a per-app (and per-component?) resolution of the CDO handle referenced in the PM protocol.

• extend pool manager protocol -- likely (appid, componentid, cdoid, unique-ifier)
• store that in cdo registry, as well as demand and withdraw registry entries, and key 'per-app' searches based on this rather than appid alone
• respect it in WITHDRAW and friends