OAK-1473: RepositoryUpgrade creates incorrect SNS names for property and child node definitions

Fix the SNS name indices.
Also address the TODO in BUILT_IN_NODE_TYPES and simplify GroupEditor by using NodeState.getName(String)

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1572229 13f79535-47bb-0310-9956-ffa450edef68