GenericBeanDefinition's toString() takes parent definition into account

Issue: SPR-9671
(cherry picked from commit 0ef29b2)
AspectJExpressionPointcut defensively handles fallback expression parsing

Issue: SPR-9335
(cherry picked from commit ce4912b)
AbstractAdvisingBeanPostProcessor uses target class check for existing proxy but checks against actual exposed object otherwise (catching introductions)

Issue: SPR-11725
(cherry picked from commit a0658c5)
ConfigurationClassEnhancer consistently uses registerStaticCallbacks in order to prevent memory leaks

Issue: SPR-9274
ConfigurationClassParser considers EnvironmentAware on ImportBeanDefinitionRegistrars

Issue: SPR-11744
Polishing