[Release Automation] Simplified release script as per blog post.
[Release Automation] Added uploadArchives target to upload the jar files to nexus.  This uses the nexus plugin and requires some magic maven incantations.
[Release Automation] Made draftReleaseNotes work as a standalone task, including uploading the JAR files.  This meant adding extra validation to make sure the release numbers are in the state we expect them to be.