Fix trace level logging. Log messages were using a message key that did not exist.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1513659 13f79535-47bb-0310-9956-ffa450edef68
Poller may return an error value with or without a value that matches a registered event.
Use i18n for debug messages.
Make debug messages consistent.
Add new debug message to show what events poller returned.
Improvements while working on a fix for BZ 55381.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1513665 13f79535-47bb-0310-9956-ffa450edef68