OAK-1877: Hourly async reindexing on an idle instance

Increase the lifetime of async indexer checkpoints to 3+ years, but
only create them when there actually are some changes in the repository.

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1601309 13f79535-47bb-0310-9956-ffa450edef68
OAK-1876: oak-run option to do diffs between TarMK revisions

Fix the path part of the oak-run debug mode options

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1601310 13f79535-47bb-0310-9956-ffa450edef68