fix some more signalling issues:

. in ONE_PROCESS mode, bail out immediately for SIGHUP and
  SIGINT

  Note that if you send HUP or INT and have cgid then cgid won't
  go away.  If you generate the interrupt signal from the httpd
  terminal then cgid will go away, [I guess] because SIGINT gets sent
  to the process group.  Perhaps just_die() needs to have logic to
  send to other processes in the group for ONE_PROCES mode

. the die_now flag should be static

. please_die_gracefully() is no longer needed


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89369 13f79535-47bb-0310-9956-ffa450edef68