Rework events

This PR reworks the events system by:

 * Remove the request on the exception event as it is already available via the exception.
 * Fix the time subscriber by storing the start time and the execution time as parameters in the request.
 * Remove the time from the journal as it is now part of the request.
 * Remove the exception passes to the retry strategy. I'm not sure about this one... Maybe I should just pass the exception as the request is already part of it and additionally, the exception can wrap the response if it is available, so, maybe just pass the exception is the good choice. My problem is it sounds strange to pass an exception to the retry strategy...
 * Move each subscriber logic into a dedicated class.
 * Refine CakePHP version (1.0 protocol version support)
 *  Don't throw exception in event subscribers (fixes #49)
 * Remove hard dependency on `symfony/event-dispatcher`