Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55629
Remove JMX notification listener when destroying servlet o.a.catalina.manager.StatusManagerServlet

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1529787 13f79535-47bb-0310-9956-ffa450edef68
Fix typo

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1529792 13f79535-47bb-0310-9956-ffa450edef68
Avoid NPE

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1529793 13f79535-47bb-0310-9956-ffa450edef68
Fix a threading/timing issue more easily observed on OSX than on Windows.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1529798 13f79535-47bb-0310-9956-ffa450edef68