registry: make certain headers optional

For a pull-only, static registry, there only a couple of headers that
need to be optional (that are presently required.
* X-Docker-Registry-Version
* X-Docker-Size
* X-Docker-Endpoints

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
registry: Info collection

roll version and standalone information into the _ping. And to support
Headers they are checked after the JSON is loaded (if there is anything
to load). To stay backwards compatible, if the _ping contents are not
able to unmarshal to RegistryInfo, do not stop, but continue with the
same behavior.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
docker daemon: show info about the server

For combing through logs, have an intro line with information about the
running instance of the docker daemon.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Add new validate-dco and validate-gofmt bundlescripts for DCO and gofmt validation

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Remove the old Travis-specific files that are no longer necessary

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Engine: optional Logging field to disable custom logging in engine.

* The default behavior is preserved
* This disables the use of the `TEST` environment variable in engine.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Move DNS options to hostconfig

The local resolver warning needed to be moved at daemon start because it
was only show for the first container started anyways before having a
default value set.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Fix edge case in bind mount absolute path detection

`filepath.Abs` does more than just `filepath.IsAbs` - namely, `filepath.Clean`, which resolves things like `.../.` or `.../../...`, and causes even an absolute path like `/some/path/../absolute` to fail (or, in my case, `/path/to/docker/.`)

Just using `filepath.IsAbs` directly is a much cheaper check, too. :)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Add contrib/man to our generated deb

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Fix a few minor man formatting consistency issues

Some flags ended with a colon, some didn't.  For man pages, the prevailing normal practice is not to end the flags lines with colons.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Update RELEASE_BUNDLES to include integration tests

Previously, running just "hack/release.sh" only ran the unit tests.  This updates that to run the unit tests, then the integration tests, then build the binaries, then run the cli integration tests (so we're literally testing the binary we're about to release, which is super freaking cool IMO <3).

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Update check-config.sh with more kernel configs and more reliable cgroup hierarchy/subsystem check

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Update test-integration-cli bundlescript for consistency with other bundlescripts and slightly more verbose logging of which commands were executed

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Added reactive-docker to list of remote API clients

Docker-DCO-1.1-Signed-off-by: H. Rapp <webmaster@3kolor.com> (github: almoehi)
Added specific error message when hitting 401 over HTTP on push
Docker-DCO-1.1-Signed-off-by: Joffrey F <joffrey@docker.com> (github: shin-)
Update DOCKER_CROSSPLATFORMS to be more readable

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
docker save: fix filemode permissions

currently the files created are not readable. This makes the files and
directories permissions more sane.

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Merge pull request #5068 from tianon/fix-abs-volume-check

Fix edge case in bind mount absolute path detection
Merge pull request #5085 from tianon/more-readable-crossplatforms-list

Update DOCKER_CROSSPLATFORMS to be more readable
Backup current docker apparmor profile and replace it with the new one

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