integcli: add some more docker utils

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
integcli: use dockerCmdInDir in build tests

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Print about "copy volume content" test passing

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Add maintainers to daemon/ and graph/

Signed-off-by: Solomon Hykes <solomon@docker.com>
Replace "amd64" build tags with "cgo" as appropriate, and remove where unnecessary

Signed-off-by: Andrew Page <admwiggin@gmail.com>
utils/broadcastwriter -> pkg/broadcastwriter

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
utils.Debugf -> log.Printf, move jsonlog to own package.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
port usage of jsonlog to the new daemon files which were refactored
recently.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Update CONTRIBUTING.md

Added link to community guidelines
Use pure go markdown processor to generate man files

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
Merge pull request #7413 from cpuguy83/7319_use_blackfriday_not_pandoc_for_manfile_gen

Use pure go markdown processor to generate man files
Merge pull request #7389 from tianon/replace-amd64-build-tags-with-cgo-as-appropriate

Replace amd64 build tags with cgo as appropriate
Only import "testing" from *_test.go

This prevents the testing package flags from leaking into the flagsets
of binaries that import docker. I left integration-cli alone.

Docker-DCO-1.1-Signed-off-by: Peter Bourgon <peter@bourgon.org> (github: peterbourgon)
Run hack/generate-authors.sh

Docker-DCO-1.1-Signed-off-by: Peter Waller <p@pwaller.net> (github: pwaller)
Change Peter Waller's canonical e-mail address

Docker-DCO-1.1-Signed-off-by: Peter Waller <p@pwaller.net> (github: pwaller)
Add a few canonicalized author names

Docker-DCO-1.1-Signed-off-by: Peter Waller <p@pwaller.net> (github: pwaller)
Regenerate AUTHORS one more time

Signed-off-by: Andrew Page <admwiggin@gmail.com>
Graphtest is ok to compile normally

The graphtest package is only imported in the test files of other
packages therefore we do not leak testing flags.

Signed-off-by: Michael Crosby <michael@docker.com>
Merge pull request #7474 from crosbymichael/testing-import

Only import "testing" in test packages
Merge pull request #7329 from erikh/move_broadcastwriter

Cleanup: utils/broadcastwriter -> pkg/broadcastwriter