OAK-960 Enable session refresh state coordination between multiple session in single thread
Encapsulation: keep the actual refreshing in SessionDelegate

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1517849 13f79535-47bb-0310-9956-ffa450edef68
OAK-960 Enable session refresh state coordination between multiple session in single thread
- Don't issue an "old session warning" when an in thread session synchronisation is pending
- Add TODOs and issue references

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1517850 13f79535-47bb-0310-9956-ffa450edef68