Bump spring-framework-bom to 4.0.4.RELEASE
Prepare for next development iteration
Add Built-Date and Implementation-Build to generated manifest
Add plugin to check classpath for duplicate classes/resources
Rename checkstyle.config property to default checkstyle.config.location
Run checkstyle on src/**/*.{java,groovy,xml,properties} and pom.xml
Checkstyle: check braces around do, else, for, while
Release version 2.1.1