LU-5017 idl: clean up file attribute flags

LU-5017 idl: clean up file attribute flags

Remove unused file attribute flag LUSTRE_BFLAG_UNCOMMITTED_WRITES
that was used internally on the client at one point.

Remove unused file attribute LUSTRE_BFLAG_EXT_FLAGS from wireshark
which was used to distinguish between S_* (in-memory) flags and
*_FL (on-disk) flags.

Add flags from the kernel which may be useful in the near future.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I39d6f26aa0fbe7b5f6ddcf31d97c959556660310
Reviewed-on: http://review.whamcloud.com/10274
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>