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)
Added support for multiple endpoints in X-Docker-Endpoints header
Docker-DCO-1.1-Signed-off-by: Joffrey F <joffrey@docker.com> (github: shin-)
typo fix: 'methid' -> 'method'
container: Remove Ghost state

container.Register() checks both IsRunning() and IsGhost(), but at
this point IsGhost() is always true if IsRunning() is true. For a
newly created container both are false, and for a restored-from-disk
container Daemon.load() sets Ghost to true if IsRunning is true. So we
just drop the IsGhost check.

This was the last call to IsGhost, so we remove It and all other
traces of the ghost state.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devicemapper: Don't mount in Create()

We used to mount in Create() to be able to create a few files that
needs to be in each device. However, this mount is problematic for
selinux, as we need to set the mount label at mount-time, and it
is not known at the time of Create().

This change just moves the file creation to first Get() call and
drops the mount from Create(). Additionally, this lets us remove
some complexities we had to avoid an extra unmount+mount cycle.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
avoid suicide

container.Kill() might read a pid of 0 from
container.State.Pid due to losing a race with
container.monitor() calling
container.State.SetStopped(). Sending a SIGKILL to
pid 0 is undesirable as "If pid equals 0, then sig
is sent to every process in the process group of
the calling process."

Docker-DCO-1.1-Signed-off-by: Daniel Norberg <daniel.norberg@gmail.com> (github: danielnorberg)
Add exported status code from a job

This allows the job's status code to be consumed externally so that we
can use it as an exit code or saving to a state file.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
 - unix://path/to/socket should read unix:///path/to/socket like the rest of the documentation (a slash was missing)
 - Mention that [] options may be specified multiple times on the Usage page

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

Docker-DCO-1.1-Signed-off-by: Mike MacCana <mike.maccana@gmail.com> (github: SvenDowideit)
add a reference to multiple -H options, and update the other example of -H option

and copy changes to the cli.md file

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Docs: Add docs new version files created by `make docs` to .gitignore

Files are:

 - docs/AWS_S3_BUCKET
 - docs/GIT_BRANCH
 - docs/VERSION

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)

Update:

 - Remove unnecessary last blankline
Docs auto-conversion fixes and MD marking and structure improvements.

 - Remove redundant chars and all errors caused by RST->MD conversion.
   e.g. [/#, /\, \<, />, etc.]
 - Fix broken inter-document links
 - Fix outbound links no-longer active or changed
 - Fix lists
 - Fix code blocks
 - Correct apostrophes
 - Replace redundant inline note marks for code with code marks
 - Fix broken image links
 - Remove non-functional title links
 - Correct broken cross-docs links
 - Improve readability

Note: This PR does not try to fix/amend:

 - Grammatical errors
 - Lexical errors
 - Linguistic-logic errors etc.

It just aims to fix main structural or conversion errors to serve as
a base for further amendments that will cover others including but
not limited to those mentioned above.

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)

Update:

 - Fix backtick issues

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Looking into some broken links, I noticed that we don't need to use
relative paths, and also fixed some broken images.

There are still more todo - next PR I think :)

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Merge pull request #5377 from SvenDowideit/fix-terms-links

Merged.
initial version of installation on ubuntu 14.04 LTS

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Fix stray url from beta-docs warning (remove aws bucket URI)

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Add support for cpu hardcapping to cgroups.
Docker-DCO-1.1-Signed-off-by: Rohit Jnagal <jnagal@google.com> (github: rjnagal)
Merge pull request #5356 from alexlarsson/devmapper-no-mount-in-create

devicemapper: Don't mount in Create()
Merge pull request #5381 from rjnagal/master

Add support for cpu hardcapping to cgroups.
Move apparmor into security sub dir
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)