Revised scheduling lifecycle integration

ScheduledAnnotationBeanPostProcessor uses getBean(Class) for TaskScheduler/ScheduledExecutorService retrieval, allowing for a scheduler bean to be flagged as primary, and for a TaskScheduler bean to override a ScheduledExecutorService bean.

ContextLifecycleScheduledTaskRegistrar hooks into SmartInitializingSingleton's afterSingletonsInstantiated callback instead of ContextRefreshedEvent, as a natural consequence of SmartInitializingSingleton's introduction in Spring Framework 4.1 GA.
BeanDefinitionValueResolver preserves original String array if possible and resolves nested String arrays as well

Issue: SPR-12391