OAK-1805: Debugging console

Simplify console arguments and document feature.

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1596569 13f79535-47bb-0310-9956-ffa450edef68
doc: Some SegmentMK doc improvements

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1596573 13f79535-47bb-0310-9956-ffa450edef68