Merge r1866078 from trunk:

Merge r1866078 from trunk:

* Make it obsolete to supply a starting pool

  Improve dump_all_pools by making it obsolete to supply a starting pool.
  If the parameter is not supplied ap_pglobal which is a global symbol is
  used as starting pool.
  The pool parameter is still accepted and considered for backwards
  compatibility or if ap_pglobal cannot be resolved.

Submitted by: rpluem

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1866656 13f79535-47bb-0310-9956-ffa450edef68