Add private 0-arg ctor for Jackson XML and JSON IO. Working toward new XML and JSON Serialization and Deserialization.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1594066 13f79535-47bb-0310-9956-ffa450edef68
Comment out console output in unit tests.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1594070 13f79535-47bb-0310-9956-ffa450edef68