Issue #88: Refactor event handling
Issue #88: Refactor event handling

- Move CommandHandlerEvent implementation into BehaviorEventable
- Make events immutable by default

nooku/nooku-platform,nooku/nooku-platform,nooku/nooku-platform,timble/kodekit-platform,nooku/nooku-platform,nooku/nooku-platform,timble/kodekit-platform,timble/kodekit-platform,timble/kodekit-platform,timble/kodekit-platform