apply some fixes from OpenBSD and don't apply some others

but sync RCS IDs for easier future adaption:
* Simplify savefd() by removing the "noclose" flag and make noclose
  behavior the default. Almost all uses of savefd() are followed
  by an implicit or explicit close.
* fix typos
* might as well make ksh_getopt() match real getopt(), ie. get rid of that
  stupid EOF concept that was never true. adobriyan@gmail
* use SEEK_* for lseek()
* fix lint comments, no functional changes
* remove excessive optimization; from adobriyan@gmail
* only santa checks things twice; from adobriyan@gmail
* Interpret zero-filled numbers as decimal; PR 4213; from Alexey Dobriyan

tree.c

@@ -1,8 +1,8 @@
-/*	$OpenBSD: tree.c,v 1.17 2005/03/30 17:16:37 deraadt Exp $	*/
+/*	$OpenBSD: tree.c,v 1.18 2006/04/10 14:38:59 jaredy Exp $	*/
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.3 2005/11/22 18:40:44 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.4 2006/05/10 18:54:13 tg Exp $");
 
 #define INDENT	4