Fix/rebind and ha 20140606

Fixes from the field, using persist+rebind.

We should first merge https://github.com/brooklyncentral/brooklyn/pull/1452, and then rebase this PR.

not so nice that the persistence logic is slightly different for each of these.  worth adding an explanation why this is necessary.  (and unifying it all eventually but a note here will help us when we come to do that!)