Add support of YAML

This commit migrates the YAML support available in Spring Boot to
the core framework. YAML documents can be loaded either as a
properties object or as a map.

Issue: SPR-9897
Additional tests for configuration class importing via ASM

Issue: SPR-11647
Eventual removal of deprecated AbstractBeanConfigurerAspect, BeanReferenceFactoryBean and CommonsLogFactoryBean
Fixed Xml/AnnotationBeanConfigurerTests after AbstractBeanConfigurerTests removal