mpm_unix(es): cleanup properly on exit in one_process mode.

We can destroy ap_pglobal in the MPMs because clean_child_exit() runs in
a DSO which would be unloaded under us.

So we defer an ap_terminate() with atexit() in ap_unixd_mpm_set_signals(),
all this is static/builtin code in "os/unix/unixd.c".



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1822537 13f79535-47bb-0310-9956-ffa450edef68