- I had some problems when shutting down pollers which had active connections in...

- I had some problems when shutting down pollers which had active connections in them. I can't
  reproduce any problem anymore, unfortunately, but I think it was because there was a poll going
  on while the sockets in the poller were being destroyed, which could then lead to these sockets
  being destroyed again. So I'm adding code to wait until the poll call is done before doing the
  poller stop.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc6.0.x/trunk@410095 13f79535-47bb-0310-9956-ffa450edef68