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.

this of course is all being thrown away now, but do we need to take note of anything being done here?

the two real `LookupContext` instances are the `RebindContextLC` (the real one) and the (test-only) `LCImpl`.  both simply lookup in a map.  (the map for the real one is populated by creating entities based on spec so it is probably already a proxy so i think we're fine but wanted to flag it.)