Restore "cometNotify" that is part of the callback mechanism used in the async code as well as Comet

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1636748 13f79535-47bb-0310-9956-ffa450edef68
s/cometNotify/callBackNotify/ since this is not Comet specific

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1636751 13f79535-47bb-0310-9956-ffa450edef68