OAK-1235 Upgrade should not overwrite new oak specific builtin nodetypes

- run InitialContent on target repository before copy
- ignore built-in nodetypes on nodetype copy

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1546384 13f79535-47bb-0310-9956-ffa450edef68