Javadoc typo.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575543 13f79535-47bb-0310-9956-ffa450edef68
Add isBlocking util method, like in AbstractOutputBuffer.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575544 13f79535-47bb-0310-9956-ffa450edef68
Add harmonized util methods for the five listener events.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575545 13f79535-47bb-0310-9956-ffa450edef68