Add README.md file for the docker directory

See issue #5873

Docker-DCO-1.1-Signed-off-by: Timothy <timothyhobbs@seznam.cz> (github: https://github.com/timthelion)
utils: add test for TimeoutConn

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: proppy)
Add integration test for history command and fix bug where history
would occasionally be returned in the incorrect order if sequential
layers had the same created time.

Docker-DCO-1.1-Signed-off-by: Bryan Murphy <bmurphy1976@gmail.com> (github: bmurphy1976)
MAINTAINERS: add proppy for google.md

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: proppy)
Fix minor bug in contrib/man/md/md2man-all.sh causing the creation of contrib/man/manREADME

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
do not alter json in docker save

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
improve test

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
add a test using the flags

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
adding a little uniqueness, to wrapped errors.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Add security message to readme
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
allow utimes on mac os, only lutimes isn't supported

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
use a numbered list for maintainers responsibility

At the moment maintainers responsibility are spelled out with a hybrid
list. I.e. an unordered list with an associated number.

In this commit I the number list proper is used.

Docker-DCO-1.1-Signed-off-by: Daan van Berkel <daan.v.berkel.1980@email.com> (github: dvberkel)
Merge pull request #6487 from vbatts/vbatts-error_info

adding a little uniqueness, to wrapped errors.
Wrap lines in security notice
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Fix go vet errors

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Merge pull request #6495 from vieux/pr_6269

Fix go vet errors
Merge pull request #6399 from dvberkel/master

use a numbered list for maintainers responsibility
Merge pull request #5878 from timthelion/docs-docker-readme

Add README.md file for the docker directory
More verbose error for parallel pull

Partially fixes #6484
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Validate that one of streams choosen in logs on api side

Fixes #6506

There is the bug, that very hard to fix: When we return job.Errorf in
"logs" job it writes to job.Stderr, to which connected ResponseWriter and on
this write w.WriteHeader(http.StatusOK) is called. So, we get 200 on error
from "logs" job.

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)