* Add some event callbacks, #aasm_event_fired(from, to), and #aasm_event_failed(event)
  Based on transition logging suggestion [Artem Vasiliev] and timestamp column suggestion [Mike Ferrier]

* Add #aasm_events_for_state and #aasm_events_for_current_state [Joao Paulo Lins]

* Ensure that a state is written for a new record even if aasm_current_state or
  {state}= are never called.

* Fix AR persistence so new records have their state set. [Joao Paulo Lins]

* Make #event! methods return a boolean [Joel Chippindale]