fix a bug in --disable-doc handling, and add snapfs to DISTDIRS

r=eeb
This patch fixes the LBUG by clearing the bits that indicate that the
OST/echo_server is sending valid cache grant information.

Li Zongliang tested this patch but was unable to check it in.

- remove extN/ files

- client-side I/O cache
- O_DIRECT fixes for IA64
- liblustre improvements
- various small bug fixes

Fixes a _huge_ number of bugs:
  - Fully reactivate OST imports after reconnection (512, others)
  - Make sure client sees our -ENOTCONN from mds_handle (513 - partial)
  - More graceful error handling for truncating on dead OST (515)
  - Don't error out unless we're actually accessing dead stripes (474)
  - Fix garbage sizes when stripes are missing (410)
  - LRU counters were broken, causing constant lock purge (433, 432)
  - garbage on read from stripes with failed OSTs (441)
  - mark OSCs as active before reconnecting during recovery (438)
  - lov_enqueue and lov_cancel need to handle inactive OSTs (403)
  - lfind did not preserve OST order in output (443)
  - symlinks cause hung clients, incorrect data (439)
  - stop dereferencing request after dropping refcount (457)
  - don't LASSERT(spin_is_locked) on non-SMP (455)
  - fixes for many rename() bugs
  - fstat didn't correctly synchronize attributes (399)
  - server must handle lock cancellation during blocking AST prep (487)
  - bulk descriptors were free()d too soon (511)
  - fix paths in lconf, which would load incorrect modules (451, 507)
  - fix confusing lconf 'host not found' error message (386)
  - fix lock order deadlock on OST (O/R i_sem before journal ops, 478)
  - fix race condition in mdc_blocking_ast() for inode access (526)
  - fix lov_unpackmd() unpacking wrong number of stripes (537)
  - fix lov_set_osc_active() marking wrong OSC inactive (440)
  - fix bad lstripe lov_unpackmd() assertion (fix layering too) (527)
  - fix multiple writes of stripe MD to MDS (358, maybe 519)
  - fix lstripe in several ways (kernel side) (527)
  - fix request leak in ldlm_cli_enqueue (262)
  - incorrect OSC was marked inactive after OST failure
  - call mds_fs_cleanup before unmounting filesystem (524)
  - fix races between taking ns_lock and ldlm_lock_change_resource
  - fix races updating LOV export open file list
  - fix lov_enqueue error path, avoid decref-ing bad lock handle
  - fix recovery NULL deref in ldlm_cli_cancel_unused
  - fix some DLM races by using new hash table for lock handles (419)
  - permit the client to specify desired inodes, at replay
  - duplicate requests when we queue them for replay reintegration
  - fix last_rcvd offset calculation
  - sync after each recovered transaction, so we always make progress
  - never, not always, ERESTART requests without transnos
  - store the lov_desc in the MDS, so we don't depend on getlovinfo to set it
  - skip replay if the MDS says that the client is already connected
  - don't check for a recovery-enabled export to match lctl's UUID
  - don't INC_USE_COUNT for phantom exports
  - don't crash when cleaning up phantom exports (567)
  - don't double-finish or set replay data for errored mdc_open requests
  - abort requests when they time out, so we don't get old replies
  - send/receive replies for AST messages again
  - if the client says that it doesn't have the lock, cancel it on the server
  - if we timeout during I/O, don't try to cancel an in-use lock; instead
    mark it as destroyed, it will all work out when decref is called
  - fix module use counts (22, 581)
 * protocol changes
  - ASTs now expect a reply (server cancels lock on error reply)

- fixes of many metadata bugs:
  - multiple client file opens
  - missing/extra intent releases
  - symlink fixes
- OST/MDS server threads clobbering each other
  - dbench 2 works mostly
- many others too numerous to mention here (ChangeLog is a good record)

  andreas on 2.5

- more fixes for 2.5 builds, much overlap with Andreas' check in from
  yesterday.

- add vfs_inode to Lustre inode info: for 2.5 this makes this the
  whole inode.

- two versions of intent_release: Robert's and the new one for 2.5

- Robert's patch - so this may break some stuff, we'll sort that out.

- convert device numbers

- small fixes to make thread handling compatible with 2.5

- always compile super25.c and super.c; the contents is conditional on
  the version

- some of page.c wasn't used by anything, so I removed those bits; much of
  page.c was only used in one module, so those bits moved there; two functions
  were shared, so now they're in obdclass; page.c is no more.
- stop building and distributing obdfs
- little warning and formatting fixups that I noticed along the way

we need initially.  The most pervasive change is the introduction
of "lov_stripe_md" throughout the code.

In addtion several small little bugs were nailed in the locking --
more are outstanding.

The setup scripts are not yet capable of running this code.

Kernel patches were updated to include LOOKUP (to let runtests.sh
work).

  this patch
- the mds has a new lovconfig command to tell it the UUID's and
  default striping pattern of the targets it needs to use (these are
  the UUID's of the OSC's typically).
- To make this scalable I changed some of the memory management in the
  class ioctl handling
- The LOV device has a trivial attach method and setup only tells it
  what MDC to use to get its information, by giving it the MDC-UUID.
- As discussed before, the MDS really provides the persistent storage
  for the LOV, what little it needs.  So during the obd_connect call
  for the object storage target (which is made from read_super) the
  storage target learns how it is striped and then connects to all the
  targets.
- We are in need of better configuration scripts for this stuff and
  tomorrow we will push the XML configurations a little further.
- Updated the documentation
- Began to cleanup the /proc/lustre/ stuff -- have some neat ideas
  about that and SNMP now.

- bring spec file uptodate
- add rpms rule to main Makefile.am

work in sync.
- This is a fairly pervasive change to get away from "device
  numbers".
- Introduce connection handles everywhere (treat these as
  lustre_handles).
- On targets map UUID's to handles upon connect and use those handles
  in the future.

  yet.

- API improvements.
- Documentation update.

- Considerable intent locking infrastructure, but it's not working perfectly
  yet.
- Updated documentation
- Many bugs.  Hold on.
- Test script changes to allow multiple mounts

I'll leave the branch around for a day or two in case we somehow missed
anything, then it will die.