Update nsinit to be nicer to work with and test
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Update for nsenter
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Move remount as private to the graph drivers

If this is at the root directory for the daemon you could unmount
somones filesystem when you stop docker and this is actually only needed
for the palces that the graph drivers mount the container's root
    filesystems.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6221 from crosbymichael/no-unmount

Move remount as private to the graph drivers
Merge pull request #6207 from crosbymichael/nsinit-cli

Make nsinit nicer to work with libcontainer
More minor copy edits, typo fix.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredfl)
Don't compile nsinit
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6227 from crosbymichael/fix-test-compile

Don't compile nsinit during tests (it has package main)
Merge pull request #6226 from fredlf/copyedits

More minor copy edits, typo fix.
start containers after all of them are registered

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
add wait4 after kill

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #6228 from vieux/fix_restart_links

Fix restart links
Bump version to v0.12.0

Docker-DCO-1.1-Signed-off-by: Tibor Vass <teabee89@gmail.com> (github: tiborvass)
Merge pull request #6230 from tiborvass/bump_v0.12.0

Bump version to v0.12.0
Change version to 0.12.0-dev

Docker-DCO-1.1-Signed-off-by: Tibor Vass <teabee89@gmail.com> (github: tiborvass)
Merge pull request #6238 from tiborvass/merge_release_v0.12.0

Merge release v0.12.0
Mention bugfixes in 0.12 changelog
devmapper: use 'user_xattr' as mountoption for ext4 - fixes #6189

># docker pull centos
># docker run -i -t centos /bin/bash

~~~
bash-4.1# touch file
bash-4.1# setfattr -n user.attr -v 1 file
setfattr: file: Operation not permitted
~~~

With 'user_xattr' as mount option

~~~
bash-4.1# touch file
bash-4.1# setfattr -n user.attr -v 1 file
bash-4.1# getfattr -d -m. file
>#file: file
user.xattr="1"
~~~

Docker-DCO-1.1-Signed-off-by: Harshavardhana <fharshav@redhat.com> (github: harshavardhana)
bring in image layer user xattr support - fixes #6189

Docker-DCO-1.1-Signed-off-by: Harshavardhana <fharshav@redhat.com> (github: harshavardhana)