illumos gate

While at it:

In cmd/w/w.c: 235

       /*                                                                                                                                                
        * read the UTMP_FILE (contains information about each logged in user)
        */                                                                                                                                               
        if (stat(UTMPX_FILE, &sbuf) == ERR) {

comment should match the code. Comment should say `read the UTMPX_FILE'

Excerpt from Marcel's review comments:

While on this, I suggest to do similar fixes here too:

http://src.illumos.org/source/xref/illumos-gate/usr/src/cmd/acct/utmp2wtmp.c#58
http://src.illumos.org/source/xref/illumos-gate/usr/src/cmd/wall/wall.c#317

and maybe here as well:

http://src.illumos.org/source/xref/illumos-gate/usr/src/cmd/utmpd/utmpd.c#962

In addition, this is in the getutxent(3c) man page:

For records of type USER_PROCESS, the nonuser() and nonuserx() macros
       use the value of the ut_exit.e_exit member to mark utmpx entries as
       real logins (as opposed to multiple xterms started by the same user on
       a window system).  This allows the system utilities that display users
       to obtain an accurate indication of the number of actual users, while
       still permitting each pty to have a utmpx record (as most applications
       expect.). The NONROOT_USER macro defines the value that login places in
       the ut_exit.e_exit member.

and I see two problems there:

1) the nonuser() macro shouldn't be mentioned here.
2) we should change NONROOT_USER to NONROOT_USRX. (Note: NONROOT_USER is a
typo in any case, the correct name is NONROOT_USR for the utmp entries).

I'd really appreciate to see all of that fixed.