HP-UX needs _HPUX_ALT_XOPEN_SOCKET_API to be defined to be able to
use various POSIX versions of networking functions.  Notably sendmsg()
resulted in "sendmsg() failed (9: Bad file number)" alerts without it.

See xopen_networking(7) for more details.

This fixes alignment problems observerd on ARMs, and likely also needed
for MIPSes.  Unless we know alignment is not required just assume we
need 16, which appears to be safe default for all architectures.

See here for details:
http://mailman.nginx.org/pipermail/nginx/2012-June/034139.html

*) Darwin sendfile() support

style fix

    *) Feature: the "server_names" directive supports the ".domain.tld"
       names.

    *) Feature: the "server_names" directive uses the hash for the
       "*.domain.tld" names and more effective hash for usual names.

    *) Change: the "server_names_hash_max_size" and
       "server_names_hash_bucket_size" directives.

    *) Change: the "server_names_hash" and "server_names_hash_threshold"
       directives were canceled.

    *) Feature: the "valid_referers" directive uses the hash site names.

    *) Change: now the "valid_referers" directive checks the site names
       only without the URI part.

    *) Bugfix: some ".domain.tld" names incorrectly processed by the
       ngx_http_map_module.

    *) Bugfix: segmentation fault was occurred if configuration file did
       not exist; the bug had appeared in 0.3.12.

    *) Bugfix: on 64-bit platforms segmentation fault may occurred on
       start; the bug had appeared in 0.3.16.