fix(CONTRIBUTING): Developer Certificate of Origin w/o Grant

In 7fb55f77250a9b52b0515a7e655ecc605ae452ca the DCO lost the grant so
change the title back to just DCO.

Docker-DCO-1.1-Signed-off-by: Brandon Philips <brandon.philips@coreos.com> (github: philips)
Adjust test to match its comment

Docker-DCO-1.1-Signed-off-by: Andrew Williams <williams.andrew@gmail.com> (github: TheDude05)
Update fixme
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4152 from crosbymichael/update-fixme

Update fixme
Remove unused reflink files
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Cleanup some statements from exec driver work
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4160 from crosbymichael/cleanup-exec-drivers

Cleanup some statements from exec driver work
Fix engine tests on systems where temp directories are symlinked.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Document Darwin test failure in a FIXME

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Refactor utility `MkBuildContext` to the more generic `archive.Generate`

This facilitates refactoring commands.go.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Move remote api client to api/

This moves `commands.go` out of the core and into `api/client.go`

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Remove duplicate function displayablePorts

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
api/container.go: an API-specific representation of a container

This breaks the dependency from the remote API implementation to the
internal representation of a container. Instead it uses its own partial
representation of a container, with only required fields.

* This preserves reverse-compatibility with all past implementations of the remote API.

* This clarifies which fields are guaranteed to be present in a response
	A docker remote api server *may* return more fields in a Container
	object, but their presence and semantics are not guaranteed and should
	not be relied upon by client implementations.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Merge pull request #4102 from shykes/separate-mkbuildclient

Refactor utility `MkBuildContext` to the more generic `archive.Generate`
Merge pull request #4107 from shykes/separate-api-client

Move remote API client out of the core and into api/
`docker cp` error when container doesn't exist

Fix cp api to return a 404 notfound if container doesn't exist.
Fixes #4119.

Docker-DCO-1.1-Signed-off-by: Fabio Falci <fabiofalci@gmail.com> (github: fabiofalci)
change the -H TCP / docker group warning to not reference a resolved issue

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
add a little reenforcement to the help for docker build -q

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Test for save and load commands

Improve test for save to tar and load from tar commands.
Docker-DCO-1.1-Signed-off-by: Fabio Falci <fabiofalci@gmail.com> (github: fabiofalci)
Add dockerode NodeJS implementation
Also correctly case 'JavaScript'

Docker-DCO-1.1-Signed-off-by: Mike MacCana <mike.maccana@gmail.com> (github: mikemaccana)