Consistently accept empty Content-Type header and empty character encoding

Issue: SPR-12173
(cherry picked from commit d501137)
Reimplemented ServerEndpointExporter to avoid BeanPostProcessor role

Issue: SPR-12340
(cherry picked from commit 10328f1)
AnnotationUtils consistently logs introspection failures via lazily initialized logger

Issue: SPR-12325
Issue: SPR-12329
Latest dependency updates (Hibernate 4.2.15, Tiles 3.0.5)
Test for ImportBeanDefinitionRegistrar double scan

Issue: SPR-12334
(cherry picked from commit 38030ef)
Polishing