improve selectsave handling for Windows

If there were outdated savefiles encountered during
startup, each individual one was getting a wait_synch
that required a <return> even though a message window
wasn't being used at that point.

Allow suppression of the individual per-file wait_synch()
calls on Windows, so that a single one can be done once
the selectsave processing is overwith.

This was a little messy because an indicator had to flow
down through validate(), uptodate(), etc.

There shouldn't be any change in how things behave on
any non-Windows platforms.

sys/share/pcunix.c

@@ -34,44 +34,6 @@ static struct stat hbuf;
 static int eraseoldlocks(void);
 #endif
 
-#if 0
-int
-uptodate(int fd)
-{
-#ifdef WANT_GETHDATE
-    if(fstat(fd, &buf)) {
-        pline("Cannot get status of saved level? ");
-        return(0);
-    }
-    if(buf.st_mtime < hbuf.st_mtime) {
-        pline("Saved level is out of date. ");
-        return(0);
-    }
-#else
-#if (defined(MICRO)) && !defined(NO_FSTAT)
-    if(fstat(fd, &buf)) {
-        if(gm.moves > 1) pline("Cannot get status of saved level? ");
-        else pline("Cannot get status of saved game.");
-        return(0);
-    } 
-    if(comp_times(buf.st_mtime)) { 
-        if(gm.moves > 1) pline("Saved level is out of date.");
-        else pline("Saved game is out of date. ");
-        /* This problem occurs enough times we need to give the player
-         * some more information about what causes it, and how to fix.
-         */
-#ifdef MSDOS
-        pline("Make sure that your system's date and time are correct.");
-        pline("They must be more current than NetHack.EXE's date/time stamp.");
-#endif /* MSDOS */
-        return(0);
-    }
-#endif /* MICRO */
-#endif /* WANT_GETHDATE */
-    return(1);
-}
-#endif
-
 #if defined(PC_LOCKING)
 #if !defined(SELF_RECOVER)
 static int