Catch exceptions in worker threads so a segfault doesn't kill all active

connections in the process. When this occurs, a graceful shutdown of the
child is initiated so any leaked resources & hosed memory is disposed of ASAP.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90400 13f79535-47bb-0310-9956-ffa450edef68