Concrete BeanFactory-based PointcutAdvisor that allows for any Advice
to be configured as reference to an Advice bean in the BeanFactory,
as well as the Pointcut to be configured through a bean property.
Specifying the name of an advice bean instead of the advice object itself
(if running within a BeanFactory) increases loose coupling at initialization time,
in order to not initialize the advice object until the pointcut actually matches.