use `BrooklynFeatureEnablement` to set whether standby or hot-standby should be the default.
failure going to hot_standby sets not to failure state, not standby state.
rename `EntityReadOnlyInternal` to `EntityTransientCopyInternal`, and remove setDisplayName, as per code review.
better tests (working) for propagating initial items, and test (failing) for update/removal of items being rebinded.
Ensure BrooklynObject management, remanagement, and unmanagement, by replacing Location instances, refreshing the catalog, and swapping out the delegate but keeping the entity proxy.
Better memory leak testing, fixing some leaks, including escaped proxy/reference chains,
and an issue with subscriptions not being cleared when children are removed
(which it turned out was there previously).