OAK-1104: SegmentNodeStore rebase operation assumes wrong child node order

Use unsigned comparison of the hash values in MapRecord to avoid unexpected ordering

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1534199 13f79535-47bb-0310-9956-ffa450edef68
OAK-527: permissions (minor improvement)

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1534200 13f79535-47bb-0310-9956-ffa450edef68