Cherry-picked following commits from
git://fuse.git.sourceforge.net/gitroot/fuse/fuse
form 555d6b50..acc5c79d interval:

  commit 1193a39c0869a3608f22472735bcffdcccb6b2a5
  Author: Reuben Hawkins <reubenhwk@gmail.com>

      cleaning up warnings

  commit dba9185999dfa35161d4c810735df0ab3fde5104
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Check the 'mtablock' for negative value

  commit e63a9d8ee6529c9d15a87745276f45c9bdad3961
  Author: Miklos Szeredi <miklos@szeredi.hu>

      fusermount: clean up do_mount() function

  commit 81fee822a098a3e26969401fc486f136465f96f0
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Eliminate the unused value

  commit 60eb44ee5eb2756465610b215968f176f4aaac6e
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Fix resource leaks in fusermount

  commit d6bec4020fddd4dd67248789a1af600580f2cbda
  Author: Miklos Szeredi <mszeredi@suse.cz>

      In case of failure to add to /etc/mtab don't umount.

  commit 1e7607ff89c65b005f69e27aeb1649d624099873
  Author: Miklos Szeredi <mszeredi@suse.cz>

      fusermount: chdir to / before performing mount/umount

  commit 2fcbc2a5a94983813c533c015134c6974f8ee636
  Author: Miklos Szeredi <miklos@szeredi.hu>

      fusermount: don't save/restore cwd

  commit bd99f9cf24e16643752b02fb4fa7b48f2124ab4e
  Author: Miklos Szeredi <miklos@szeredi.hu>

      Fix check for read-only fs in mtab update

Nb.:
- not picked changes that implement and enforce mount/umount
  mechanisms based on newer util-linux features (umount --fake
  and --no-canonicalize)
- not picked fusermount "auto-unmount" feature

Change-Id: Ib9498516184336e77ec047e5414125332d0a4292
BUG: 762389
Signed-off-by: Csaba Henk <csaba@redhat.com>
Reviewed-on: http://review.gluster.com/3343
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

Macro-driven conditional compilation was a chaos.

New scheme is:

contrib/fuse-lib/mount-common.c:
  libfuse routines used both by glusterfs and fusermount
contrib/fuse-lib/mount.c:
  libfuse-derived but customized mounting code for glusterfs
contrib/fuse-util/mount_util.c:
  libfuse routines used only by fusermount

Change-Id: I3e0ba7f74e36556b78244cd7676eb4d379939602
BUG: 762389
Signed-off-by: Csaba Henk <csaba@redhat.com>
Reviewed-on: http://review.gluster.com/3342
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>