Simplify. Have a single method adding sockets to the Poller's addList

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1441916 13f79535-47bb-0310-9956-ffa450edef68
Make sure a socket doesn't get left in limbo if it is passed to Poller.add() after the Poller has stopped (which may happen with a long running request thread).

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1441920 13f79535-47bb-0310-9956-ffa450edef68