OAK-301 : oak docu

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1595182 13f79535-47bb-0310-9956-ffa450edef68
OAK-1834 - DS.query: add tests for query collations, also catch fire when collation is incorrect

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1595183 13f79535-47bb-0310-9956-ffa450edef68
OAK-1833: Logging in and out many sessions leads to high memory consumption
Move counters back from SessionDelegate to SessionStats such that we can remove the reference from the latter to the former

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1595186 13f79535-47bb-0310-9956-ffa450edef68