Tru64 SSI_FD_NEWMAX patch

Attached ugly patch attempts to add Tru64 SSI_FD_NEWMAX support to
nginx. This allows nginx under Tru64 to use up to 64k FDs instead of
just 4k.

Technical details are at:
http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V40F_HTML/AQ0R3GTE/CHLMTSXX.HTM#fs-limits

-Dustin, probably the lone Tru64 nginx user :slight_smile: