Update hack/dind to mount cgroups on "/cgroup" instead of "/sys/fs/cgroup" for better compatibility

Fixes #5122

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Adding Rohit Jnagal and Victor Marmol to pkg/cgroups maintainers.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
Introduce x-axe scrolling to code-blocks.

This improvement introduces x-axe scrolling to code-blocks by
overriding certain default bootstrap word-wrapping constraints.

This PR closes: https://github.com/dotcloud/docker/issues/5279

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Change owner only on copied content

Fixes #5110
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
move Table to a separate file and add additional unit tests

Docker-DCO-1.1-Signed-off-by: Bryan Murphy <bmurphy1976@gmail.com> (github: bmurphy1976)
Update restrict.Restrict to both show the error message when failing to mount /dev/null over /proc/kcore, and to ignore "not exists" errors while doing so (for when CONFIG_PROC_KCORE=n in the kernel)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #5535 from vmarmol/add-maintainers-cgroup

Adding Rohit Jnagal and Victor Marmol to pkg/cgroups maintainers.
Fix link to daemon/execdriver/lxc/lxc_template.go
Fixed typo in docs - intro - working with docker - working with images.  It read that you can use both images used by others and images used by others, in a run-on sentence.
Merge pull request #5673 from tianon/kcore-error

Update restrict.Restrict to both show the error message when failing to mount /dev/null over /proc/kcore, and to ignore "not exists" errors while doing so (for when CONFIG_PROC_KCORE=n in the kernel)
devmapper: Remove accidental debug spew

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #5680 from alexlarsson/dm-remove-spew

devmapper: Remove accidental debug spew
Merge pull request #5679 from tdaws/master

Fixed typo in docs - intro - working with docker - working with images. ...
Cast Input and Output to closer
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
make higher level heading specify that instructions are for manual install

Docker-DCO-1.1-Signed-off-by: Benjamin Atkin <ben@benatkin.com> (github: benatkin)
Merge pull request #5116 from LK4D4/chown_only_on_content_#5110
Merge pull request #5561 from bmurphy1976/bmurphy1976-table-tests
rename goruntime import to runtime

This renames the goruntime import of the runtime package back to
runtime.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #5540 from unclejack/imports_cleanup
Merge pull request #5689 from benatkin/doc-osx-setup-section-fix

make higher level heading specify that instructions are for manual installation