* Makefile.in (DLL_OFILES): Add bsdlib.o.

* autoload.cc (RegisterServiceProcess): Add.
	* bsdlib.cc: New file.
	(daemon): New function.
	(login_tty): Ditto.
	(openpty): Ditto.
	(forkpty): Ditto.
	* cygwin.din: Export daemon, forkpty, login_tty, logwtmp, updwtmp,
	openpty and revoke.
	* syscalls.cc (updwtmp): New function, writing to wtmp exclusively.
	(logwtmp): Ditto.
	(login): Call updwtmp instead of writing to wtmp by itself.
	(logout): Ditto.
	* tty.cc (revoke): New funtion.
	* include/paths.h: Define _PATH_DEVNULL.
	* include/pty.h: New header.
	* include/cygwin/version.h: Bump API minor number.
	* include/sys/utmp.h: Declare logwtmp with const arguments.
	Declare updwtmp.
	* lib/iruserok.c: New file.
	(ruserok): New function.
	(iruserok): Ditto.
	(__ivaliduser): Ditto.
	(__icheckhost): Ditto.

winsup/cygwin/cygwin.din

@@ -350,6 +350,7 @@ cygwin_win32_to_posix_path_list_buf_size
 cygwin32_win32_to_posix_path_list_buf_size = cygwin_win32_to_posix_path_list_buf_size
 cygwin_winpid_to_pid
 cygwin32_winpid_to_pid = cygwin_winpid_to_pid
+daemon
 difftime
 _difftime = difftime
 dirfd
@@ -509,6 +510,7 @@ _fopen = fopen
 _fopen64 = fopen64
 fork
 _fork = fork
+forkpty
 fpathconf
 fprintf
 _fprintf = fprintf
@@ -816,7 +818,10 @@ _logbf = logbf
 logf
 _logf = logf
 login
+login_tty
 logout
+logwtmp
+updwtmp
 longjmp
 _longjmp = longjmp
 lrand48
@@ -918,6 +923,7 @@ opendir
 _opendir = opendir
 openlog
 _openlog = openlog
+openpty
 pathconf
 _pathconf = pathconf
 pause
@@ -1062,6 +1068,7 @@ remquo
 remquof
 rename
 _rename = rename
+revoke
 rewind
 _rewind = rewind
 rewinddir