System-wide events, and event bubbling from object->schema->system

[lox]

Added an new event: beforeInitialize(schemaBuilder) and afterInitialize(schema)

Now there are three points for event registration:

• System-wide:

Pheasant::instance()->events()->register('afterInitialize', function($event, $schema) {
   // do some setup for the object
});

• Schema-specific

Llamas::events()->register('beforeSave', function($event, $object) {
   // do something before saving all Llama objects
});

• Instance-specific

$llama = new Llama();
$llama->events()->register('beforeSave', function($event, $object) {
   // do some setup for the object
});

The interesting thing about this system is it bubbles. Events are fired at the most granular possible level and they bubble upwards, eventually ending up at the system event handler.