Reviewed by: Rob Hartill

Modified for AIX support by adding "HAVE_MMAP" to default defines, and
changed the SERVICE_UNAVAILABLE define (which only mod_proxy was
using) to HTTP_SERVICE_UNAVAILABLE.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76662 13f79535-47bb-0310-9956-ffa450edef68