Create branch https://svn.apache.org/repos/asf/logging/log4j/log4j2/branches/new-levels for the new levels; was VETOed from trunk by Remko Popma.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/branches/new-levels@1561304 13f79535-47bb-0310-9956-ffa450edef68