OAK-1329: Relaxed JCR locking behavior

Allow a user that owns a lock to retrieve it's token even with a session
that does not currently hold the lock

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1564523 13f79535-47bb-0310-9956-ffa450edef68
OAK-150: Basic JCR LockManager support

Document the "fuzzy locking" strategy used by Oak

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1564524 13f79535-47bb-0310-9956-ffa450edef68