Review Request: Improve Logger javadoc for throwing() and catching()

[Volkan Yazıcı]

Hello,

Would anybody mind reviewing the javadoc changes in GitHub #466
<https://github.com/apache/logging-log4j2/pull/466> addressing LOG4J2-3020
<https://issues.apache.org/jira/browse/LOG4J2-3020> LOG4J2-3021
<https://issues.apache.org/jira/browse/LOG4J2-3021>, please?

Cheers!