Remove support for setting the date

This wasn't really being used and was too much trouble to port.
* Makefile, NEWS: Document this.
* date.c: Don't include utmpx.h or fcntl.h..
(OTIME_MSG, NTIME_MSG, WTMPX_FILE): Remove.
(main, usage): Remove support for setting the date.
Remove dummy -n option.
(reset, wildinput, oops, sametm, convert, checkfinal, iffy): Remove.

Makefile

@@ -121,7 +121,6 @@ LDLIBS=
 #  -DHAVE_SYS_WAIT_H=0 if your compiler lacks a "sys/wait.h"
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
 #  -DHAVE_UNISTD_H=0 if your compiler lacks a "unistd.h" (Microsoft C++ 7?)
-#  -DHAVE_UTMPX_H=0 if your compiler lacks a "utmpx.h"
 #  -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU=1
 #	if you do not want run time warnings about formats that may cause
 #	year 2000 grief

NEWS

@@ -48,23 +48,10 @@ Unreleased, experimental changes
     Some Visual Studio 2013 warnings have been suppressed.
     (Thanks to Kees Dekker.)
 
-    date now sets the time of day via the POSIX clock_settime function
-    instead of via the older nonstandard settimeofday function.
-    date's -a, -d, and -t options have been removed.  Long obsolescent,
-    they were usable only by the superuser, and their implementation
-    had porting problems.  Builders no longer need to configure
-    HAVE_ADJTIME and HAVE_SETTIMEOFDAY.  (Thanks to Kees Dekker for
-    pointing out the problem.)
-
-    The implementation of date's -n option, which has long been a
-    no-op in practice, has been greatly simplified and the -n option
-    is no longer documented.  (Thanks to Kees Dekker for pointing out
-    the problem.)
-
-    For recording clock changes date.c by default now includes and
-    uses <utmpx.h>, which has long been part of POSIX, and no longer
-    uses the long-obsolescent <utmp.h> API.  Compile with
-    -DHAVE_UTMPX_H=0 to suppress the use of <utmpx.h>.
+    'date' no longer sets the time of day and its -a, -d, -n and -t
+    options have been removed.  Long obsolescent, the implementation
+    of these features had porting problems.  Builders no longer need
+    to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
     (Thanks to Kees Dekker for pointing out the problem.)
 
   Changes affecting documentation