- Plug huge mem leak; mostly samba was suffering.

- Fix semantics: seekdir(pos); telldir() shoud return pos. The code
that implements this will be made faster in a later commit.
- We loose documented behaviour (after closedir() the telldir()
positions are not valid anymore). This was never in Posix, and most
other systems have nothing like it.
Diff originally from Paul Thorn, rewritten by me using some FreeBSD
code.  "slap it in" deraadt@

src/include/dirent.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: dirent.h,v 1.15 2005/12/13 00:35:22 millert Exp $	*/
+/*	$OpenBSD: dirent.h,v 1.16 2006/04/01 18:06:59 otto Exp $	*/
 /*	$NetBSD: dirent.h,v 1.9 1995/03/26 20:13:37 jtc Exp $	*/
 
 /*-
@@ -59,6 +59,7 @@
 /* definitions for library routines operating on directories. */
 #define	DIRBLKSIZ	1024
 
+struct _telldir;
 /* structure describing an open directory. */
 typedef struct _dirdesc {
 	int	dd_fd;		/* file descriptor associated with directory */
@@ -69,6 +70,7 @@ typedef struct _dirdesc {
 	long	dd_seek;	/* magic cookie returned by getdirentries */
 	long	dd_rewind;	/* magic cookie for rewinding */
 	int	dd_flags;	/* flags for readdir */
+	struct _telldir *dd_td; /* telldir position recording */
 } DIR;
 
 #define	dirfd(dirp)	((dirp)->dd_fd)
@@ -106,7 +108,7 @@ int getdirentries(int, char *, int, long *)
 		__attribute__ ((__bounded__(__string__,2,3)));
 #endif /* __BSD_VISIBLE */
 #if __XPG_VISIBLE
-long telldir(const DIR *);
+long telldir(DIR *);
 void seekdir(DIR *, long);
 #endif
 #if __POSIX_VISIBLE >= 199506 || __XPG_VISIBLE >= 500