OPENDJ-1375 CR-4618: prevent deadlocks when updating id2subtree using IndexBuffers

Lock entry ID keys in descending order (children then parents) in order to be
consistent with id2subtree updates performed for single entry add and delete
operations.


git-svn-id: https://svn.forgerock.org/opendj/branches/opendj3-server-dev@11057 41b1ffd8-f28e-4786-ab96-9950f0a78031
Actual merge of complete changelog.file test package,
which contains test cases for file-based changelog

git-svn-id: https://svn.forgerock.org/opendj/branches/opendj3-server-dev@11059 41b1ffd8-f28e-4786-ab96-9950f0a78031
Actual merge of ChangelogBackendTestCase class

git-svn-id: https://svn.forgerock.org/opendj/branches/opendj3-server-dev@11060 41b1ffd8-f28e-4786-ab96-9950f0a78031
Launch tests with file-based changelog by default


git-svn-id: https://svn.forgerock.org/opendj/branches/opendj3-server-dev@11061 41b1ffd8-f28e-4786-ab96-9950f0a78031
Attemp to fix random test in HistoricalTest class

git-svn-id: https://svn.forgerock.org/opendj/branches/opendj3-server-dev@11062 41b1ffd8-f28e-4786-ab96-9950f0a78031