Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Replace the non-standard disclaimer with the standard one from /COPYRIGHT

Approved by: jedgar@

mdoc(7) police: "The .Fn function".

mdoc(7) police: Use the new .In macro for #include statements.

Record -lposix1e merge with -lc.

mdoc(7) police:

- lowercase Nd argument
- mark function arguments with Fa
- mark defined values with Dv
- simply copying POSIX text for RETURN VALUES and ERRORS sections is not
always a good idea. POSIX uses the word "shall" indicating the behavior
the correct implementation should follow.

Add the following POSIX 1003.1e functions and man pages:
o acl_calc_mask(): calculates the ACL mask entry associated with
the given ACL.
o acl_delete_entry(): remove a specified ACL entry from the given
ACL.

Approved by: rwatson