LU-1032 build: Support --disable-maintainer mode

We add "AM_MAINTAINER_MODE([enable])" to all configure
scripts to allow us to use --disable-maintainer-mode.

By default, without the AM_MAINTAINER_MODE macro, autotools
"maintainer mode" is enabled.  By specifying "enable" we
maintain our previous default behaviour.

Change-Id: I88366ad658795145af80ed96c6e708c385799ffa
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/5423
Tested-by: Hudson
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Prakash Surya <surya1@llnl.gov>
Reviewed-by: Brian J. Murrell <brian.murrell@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
LU-2910 clio: skip iov update when tot_nrsegs is zero

When tot_nrsegs is zero, we should skip the iov update too.

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I52d4d52a65802f3967dd6a96ad46ec40fd4ef355
Reviewed-on: http://review.whamcloud.com/5747
Tested-by: Hudson
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>