Add new mutexes (sysvsem, solaris pthreads, irix uslocks).

Add SAFE_UNSERIALIZED_ACCEPT support.

Submitted by:	Dean Gaudet,
Submitted by:	Pierre-Yves Kerembellec <Pierre-Yves.Kerembellec@vtcom.fr>,
Submitted by:	Martijn Koster <m.koster@pobox.com>
Reviewed by:	Paul Sutton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78977 13f79535-47bb-0310-9956-ffa450edef68