Test bullet-proofing.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1605654 13f79535-47bb-0310-9956-ffa450edef68
Logging that an available port does not need to be at the INFO level, using DEBUG and wishing for a VERBOSE.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1605655 13f79535-47bb-0310-9956-ffa450edef68
[LOG4J2-689] Update Jackson to 2.4.1.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1605656 13f79535-47bb-0310-9956-ffa450edef68
Refactor to reuse own APIs, also give us shorter methods.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1605657 13f79535-47bb-0310-9956-ffa450edef68
Re-used AvailablePortFinder from the Core tests and remove the recently refactored FreePortFinder.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1605658 13f79535-47bb-0310-9956-ffa450edef68