Update versions in Flume documentation.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1575602 13f79535-47bb-0310-9956-ffa450edef68
Update use of status logger in Loader.

  - Uses parametrized messages.
  - Use {@code} instead of code HTML tags.
  - Add some trace logging to class loading.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1575603 13f79535-47bb-0310-9956-ffa450edef68
Update logger usage.

  - Plus some static code coverage "fixes".

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1575604 13f79535-47bb-0310-9956-ffa450edef68