Fix typo.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1615547 13f79535-47bb-0310-9956-ffa450edef68
Document Jackson requirement.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1615548 13f79535-47bb-0310-9956-ffa450edef68
Add missing Disruptor version.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1615552 13f79535-47bb-0310-9956-ffa450edef68