Mediator pattern in coffee

Mediator.coffee

## Pierre
# Implémentation d'un médiateur
###
  Mediator
    publish (event [args])
    subscribe (event, cb)
    unsubscribe (event, cb)
###
## Correction de Chistophe
Mediator =
	subscriptions:{}
	subscribe: (event, cb) ->
		container = @subscriptions[event] ?= []
		return false if cb in container
		container.push cb
		true
	unsubscribe: (event, cb) ->
		return unless container = @subscriptions[event]
		return false unless i = container.indexOf cb
		container.splice i, 1
		true
	publish: (event, args...)->
		cb args... for cb in @subscriptions[event] ? []
		true