OAK-659 Move purge logic for transient changes below the NodeBuilder interface
Avoid falling back to MemoryNodeBuilder.moveTo/copyTo in case the newParent is SecureNodeBuilder

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1525016 13f79535-47bb-0310-9956-ffa450edef68