Javadoc addition.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1620498 13f79535-47bb-0310-9956-ffa450edef68
Fix XML.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1620499 13f79535-47bb-0310-9956-ffa450edef68
Add custom SLF4J marker to demonstrate LOG4J2-793.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1620500 13f79535-47bb-0310-9956-ffa450edef68
Add custom SLF4J marker support in log4j-slf4j-impl bridge.

  - Fixes LOG4J2-793.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1620501 13f79535-47bb-0310-9956-ffa450edef68
Add changelog entry for LOG4J2-793.

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1620502 13f79535-47bb-0310-9956-ffa450edef68