DeviceMapper: Succeed immediately when removing non-existant devices

We've seen situations where removal of "ID-init" failed during
container deletion (EBUSY), after removal of "ID" has succeeded. This
caused the container delete operation to fail, and on the next delete
attempt the removal of "ID" failed immediately with "does not exist".

Ideally we should not fail the ID-init removal, but its also non-ideal
to allow a state where the container is half-removed and we cannot
make progress deleting the container. So, we silently ignore not-exist
errors on device removal.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Add per-device lock

We currently use a global lock to protect global data (like the
Devices map) as well as device data itself and access to
(non-threadsafe) libdevmapper.

This commit also adds a per-device lock, which will allow per-device
operations to temporarily release the global lock while e.g. waiting.
The per-device lock will make sure that nothing else accesses that
device while we're operating on it.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Increase sleep times and unlock while sleeping

We've seen some cases in the wild where waiting for unmount/deactivate
of devmapper devices taking a long time (several seconds). So, we increase
the sleeps to 10 seconds before we timeout. For instance:

https://github.com/dotcloud/docker/issues/4389

But, in order to not keep other processes blocked we unlock the global
dm lock while waiting to allow other devices to continue working.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
improve alpha sort in mflag

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Clarify how to update the docs branch in the RELEASE-CHECKLIST with concrete instructions

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Note within the RELEASE-CHECKLIST that "origin" is assumed to be upstream

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
handle capital

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Adding the new options to the `docker ps` documentation.

URL of documentation page is: http://docs.docker.io/en/latest/reference/commandline/cli/#ps

Docker-DCO-1.1-Signed-off-by: Scott Collier <emailscottcollier@gmail.com> (github: scollier)
Adding options to `docker restart` documentation

URL of page is: http://docs.docker.io/en/latest/reference/commandline/cli/#restart

Docker-DCO-1.1-Signed-off-by: Scott Collier <emailscottcollier@gmail.com> (github: scollier)
nsinit: prefix errors with their source

Docker-DCO-1.1-Signed-off-by: Sridhar Ratnakumar <github@srid.name> (github: srid)
Merge auth package within registry

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Merge pull request #4566 from srid/nsinit_uniq_errors

nsinit: prefix errors with their source
Move signal to pkg

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Create portable signalMap

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Make docker use the signal pkg with strings

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Merge pull request #4515 from vieux/improve_sort_flags

improve alpha sort in mflag
Merge pull request #4567 from creack/merge_auth_registry

Merge auth package within registry
Merge pull request #4520 from tianon/clarify-docs-branch-update

Clarify how to update the docs branch in the RELEASE-CHECKLIST with concrete instructions
Merge pull request #4563 from creack/signal-improvment

Signal improvments
spelling correction

s/singal/signal/

Docker-DCO-1.1-Signed-off-by: Dolph Mathews <dolph.mathews@gmail.com> (github: dolph)