Remove collection
Rename page to router
Make Scenes bind events when an instance is created
Send events with 'event' type and spare events
Dump controller's error name and message
Refactoring: Pass the received data to Controller#dispatch
Refactoring: Make GameReceiver to use 'listen'
Refactor specs

- Add `Context` for lazy definition of variables (such as RSpec)
- Move helper.js to helpers directory
Fix test

- Use argument matcher
- Suspend test which fails
Fix Game
Refactor Quest

- Add some predicate methods.
- Raise errors in some exceptional cases.
Fix bugs of Quest
Fix bugs of room#toJson
Fix bugs of Receivers
Fix bugs of database#readTeam
Enable database to create dummy data
Add database#log for logging
Add database#current{Room, Game, Quest, Team}
Enable TeamReceiver to receive 'change:Team.members'
Add ModelExtensions to enable Models to manage form data