Merge pull request #5401 from SvenDowideit/docs-api-eg-formating

small api doc formatting fixup
devmapper: Store metadata in one file per device

This allows multiple instances of the backend in different containers
to access devices (although generally only one can modify/create them).

Any old metadata is converted on the first run.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #5342 from danielnorberg/avoid-suicide

avoid suicide
Updated sample config to be usable. We should change the namespace
config to not need "value" later.

Docker-DCO-1.1-Signed-off-by: Rohit Jnagal <jnagal@google.com> (github: rjnagal)
static_registry: update the test for the new struct

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
engine.Installer: a standard interface for "installable" services

Installer is a standard interface for objects which can "install"
themselves an engine by registering handlers.

This can be used as an entrypoint for external plugins etc.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
engine: allow registering a "catchall" handler which receives all commands

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Remote communication between engines using beam

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
engine.Sender and engine.Receiver support stdin

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
engine: 'rengine' is a small command-line utility to debug remote engine

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Merge pull request #5365 from crosbymichael/job-status

Add exported status code from a job
Merge pull request #5411 from crosbymichael/lockdown

Update default restrictions for exec drivers
Adding a test for blkio stats.

Also adds a test utility we can use for other cgroup tests.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
Updated Docs README

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Merge pull request #5415 from jamtur01/readme2

Updated Docs README
Fixed Dockerise to Dockerize

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Replaced all double backticks in README with singles

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Merge pull request #5416 from jamtur01/dockerize

Fixed Dockerise to Dockerize
Merge pull request #5417 from jamtur01/readme3

Fixed double backtick to single backtick formatting issue in README
Freeze ./integration and explain where to contribute new tests

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