Standardize the async result subclasses

Move away from these subclasses exposing there properties
as publicly viewable and have them only expose the base
class functions as things that are publicly useable.

This also adjusts how the zookeeper async result had a usage
of camelcasing that didn't seem to fit in the other naming
conventions that tooz uses.

Change-Id: Iaa1dd3bb7b359b2dab14a8aeeab9f2e3e9cd8d29