Resync the DCO text with upstream at http://developercertificate.org/

```
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
```

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Remove duplication of Dns in config merging.

Fixes #4714
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
fix failing test to use kill instead of stop

TestCreateStartRestartStopStartKillRm was failing because stop has been
changed to not kill containers.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #4782 from unclejack/fix_TestCreateStartRestartStopStartKillRm

fix failing test to use kill instead of stop
Fix double single dash arg issues in docs

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
rename lxc to bridge

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #4796 from cpuguy83/fix_single_dash_args_in_dcs

Fix double single dash arg issues in docs
Added Eixo::Docker to the list of libraries

Docker-DCO-1.1-Signed-off-by: Javier Gómez <alambike@gmail.com> (github: alambike)
Merge pull request #4803 from alambike/patch-1

Added Eixo::Docker to the list of libraries
Merge pull request #4518 from tianon/sync-DCO-with-developercertificate.org

Resync the DCO text with upstream at http://developercertificate.org/
Fix since time exit display when s.FinishedAt is zero

When s.FinishedAt is zero, the since time exit in docker ps doesn't display correct time.
For example
```
Exited (0) 292.471209 years ago
```
This patch fixes the since time exit to display nothing if s.FinishedAt is zero.

Docker-DCO-1.1-Signed-off-by: Ken ICHIKAWA <ichikawa.ken@jp.fujitsu.com> (github: ichik1)
Merge pull request #4761 from ichik1/fix-display-of-since-time-exit

Fix since time exit display when s.FinishedAt is zero
Merge pull request #4800 from vieux/rename_network_driver

rename lxc to bridge
Merge pull request #4775 from LK4D4/remove_duplicate_dns_#4714

Remove duplication of Dns in config merging.