curses splash/copyright screen, role prompt

Back out '#include "date.h"' so that cursinit.c won't be recompiled
every time any other file(s) need to be compiled.  It doesn't need
patchlevel.h either.  There is already a straightforward way to fetch
the copyright banner lines from version.c.

The splash screen (ascii art spelling "NetHack" preceding the normal
copyright lines) was invisible when showing white text on white-ish
background.  Make it honor !guicolor.

"Shall I pick a character's role, race, gender and alignment for you?
 [ynaq] (y) " was too wide to accept the answer on the same line on
an 80-column display so "(y) " was placed on the second line.  That's
constructed in the core; change the construction to omit " a" when
using "character" rather than a role name.  (tty shortens it by omitting
the default " (y)"; with " a" gone, it could revert to normal prompt.)

Also a bit of lint cleanup and some reformatting of cursinit.c....

src/version.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	version.c	$NHDT-Date: 1524693365 2018/04/25 21:56:05 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.49 $ */
+/* NetHack 3.6	version.c	$NHDT-Date: 1546137502 2018/12/30 02:38:22 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.51 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2018. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -68,7 +68,8 @@ char *buf;
 #if defined(NETHACK_GIT_BRANCH)
 #if defined(BETA)
         if (NetHack_git_branch)
-            Sprintf(eos(buf), "%sbranch:%s", c++ ? "," : "", NetHack_git_branch);
+            Sprintf(eos(buf), "%sbranch:%s",
+                    c++ ? "," : "", NetHack_git_branch);
 #endif
 #endif
         Sprintf(eos(buf), ")");