Clarification of behaviour in _PersistentObjectEditPane.
Clarification of behaviour in _PersistentObjectEditPane.

* on detection of unexpected delete, go BUSY, not wild
* reactor some promise chains, using otherwise, and removing superfluous Deferreds (what was I thinking)
* added missing pre to refresh
* refresh now returns po on IdNotFoundException (this is nominal), and throws the rest (errors were eaten before)
* remove superfluous IdNotFoundException handling code in cancel (this is done in refresh already); for the other exceptions, something that will not crash until we deal with them
* some doc fixes

There are still alerts here, that should be removed!
Still need to handle SecurityException, AlreadyChanged, and other SemanticExceptions (PropertyExceptions) in a better way.
(MUDO's and TODO's)

peopleware/js-ppwcode-vernacular-persistence,peopleware/js-ppwcode-vernacular-persistence