Fix Javadoc typo
Seamless support for Groovy bean definitions mixed with XML bean definitions

GroovyBeanDefinitionReader and Groovy ApplicationContexts redirect ".xml" files to XmlBeanDefinitionReader now, similar to what they've been doing for importBeans directives already. Analogously, @ImportResource for configuration classes redirects ".groovy" to GroovyBeanDefinitionReader now.

Issue: SPR-11924
Upgrade to Reactor 1.1.3
Polishing
Prepare for upgrade to Gradle 2.0

MergePlugin now uses syntax appropriate for Gradle 2.0.

Issue: SPR-11934
Polishing
(cherry picked from commit 86ea305)