Don't close NoSQL clients on commit.

  - Related to LOG4J2-676.
  - Our NoSQL drivers are actually clients which means calling close() on them (or equivalent) is really more like shutting down the connection pool than closing an individual connection.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1604636 13f79535-47bb-0310-9956-ffa450edef68
Add javadoc to Level class.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1604638 13f79535-47bb-0310-9956-ffa450edef68
Expand on the top level package-info javadoc.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1604640 13f79535-47bb-0310-9956-ffa450edef68