OAK-1570 merged last trunk

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1600088 13f79535-47bb-0310-9956-ffa450edef68
OAK-1717 merged trunk
OAK-1717 Concurrent updates of ordered index in cluster may fail

added the strategy for managing the index and related utilities for
constructions
OAK-1717 Concurrent updates of ordered index in cluster may fail

chained the call to the strategy. Still To be tested.
OAK-1717 Concurrent updates of ordered index in cluster may fail

small refactoring
OAK-1717 Concurrent updates of ordered index in cluster may fail

added the computation of the key lenght
OAK-1717 Concurrent updates of ordered index in cluster may fail

implemented the tokenise of the input key for creating the tree. Still
to increase test coverage.