OAK-1156 - Improve the document cache invalidation logic to selectivly invalidate doc

Changing the logger category

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1543729 13f79535-47bb-0310-9956-ffa450edef68
OAK-1156 - Improve the document cache invalidation logic to selectively invalidate doc

Adding an extra check that sameLevelNodes is not empty. Otherwise unnecessary query would be performed with empty node list

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1543730 13f79535-47bb-0310-9956-ffa450edef68