Remove dawn/sunup/sunset/sundown (sunrise was never there...)

If 06:00 or 18:00 are wanted, just say "06:00" (etc).  If these
are ever added back, they really should determine location, and
calculate actual sunrise/sunset times for the location and date.
That's not likely to happen...

lib/libutil/parsedate.3

@@ -1,4 +1,4 @@
-.\"     $NetBSD: parsedate.3,v 1.20 2015/12/10 21:32:35 wiz Exp $
+.\"     $NetBSD: parsedate.3,v 1.21 2016/06/26 07:09:24 kre Exp $
 .\"
 .\" Copyright (c) 2006 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -131,11 +131,7 @@ The following words are recognized in English only:
 .Dv p.m. ,
 .Dv midnight ,
 .Dv mn ,
-.Dv noon ,
-.Dv dawn ,
-.Dv sunup ,
-.Dv sunset ,
-.Dv sundown .
+.Dv noon .
 .Pp
 The months:
 .Dv january ,

lib/libutil/parsedate.y

@@ -14,7 +14,7 @@
 
 #include <sys/cdefs.h>
 #ifdef __RCSID
-__RCSID("$NetBSD: parsedate.y,v 1.28 2016/05/03 18:14:54 kre Exp $");
+__RCSID("$NetBSD: parsedate.y,v 1.29 2016/06/26 07:09:24 kre Exp $");
 #endif
 
 #include <stdio.h>
@@ -587,10 +587,6 @@ static const TABLE TimeNames[] = {
     { "mn",		tTIME,		 0 },
     { "noon",		tTIME,		12 },
     { "midday",		tTIME,		12 },
-    { "dawn",		tTIME,		 6 },
-    { "sunup",		tTIME,		 6 },
-    { "sunset",		tTIME,		18 },
-    { "sundown",	tTIME,		18 },
     { NULL,		0,		 0 }
 };