Windows CE port fixes/enhancements (from <Someone>)

A few other fixes:
- bug: text window does not scroll left on left arrow
- pcmain.c: fix warning: _fileno() returns void* in Windows CE SDK

3.5.0 only:
- files.c: compile error: don't include <signal.h> if NO_SIGNAL is defined. WinMo does not support POSIX signals
- version.c: compile error: append_port_id() is undeclared
- link error: mktime() is unsupported -> define it in celib.c

-<Someone>

include/wceconf.h

@@ -1,5 +1,4 @@
 /* NetHack 3.5	wceconf.h	$Date$  $Revision$ */
-/*	SCCS Id: @(#)wceconf.h	3.5	2005/01/23	*/
 /* Copyright (C) 2001 by Alex Kompel 	 */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -272,6 +271,7 @@ struct tm {
 
 extern struct tm * __cdecl localtime(const time_t *);
 extern time_t __cdecl time(time_t *);
+extern time_t __cdecl mktime(struct tm * tb);
 
 /* __stdio.h__ */
 #ifndef BUFSIZ