OAK-798: Review / refactor TreeImpl and related classes
- Remove TreeLocation from API and replace usages with utility class

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1478403 13f79535-47bb-0310-9956-ffa450edef68
OAK-806: Content migration from Jackrabbit to Oak

First draft of an automatic repository upgrade tool

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1478405 13f79535-47bb-0310-9956-ffa450edef68