Merge b_intent into b_md:

Merge b_intent into b_md:

** You will need to update your kernel, Lustre patch version 8 **

Highlights:

- the MDS now returns a block count for non-regular files (for which it has
  the authoritative size information)
- we set a DCACHE_LUSTRE_INVALID flag on dentries when we alienate them; this
  flag is now used in the VFS to help us avoid a race condition with
  revalidate2 and dentry alienation
- remove the ldlm_lock_match CBPENDING flag, which severely violates a DLM
  invariant
- fix enqueue_ordered_lock matching
- we reintroduced bug 72 by accident; fixed again, with a better comment.
- small fixes to create.pl/rename.pl