Move Attach from container to daemon

This moves the Attach method from the container to the daemon.  This
method mostly supports the http attach logic and does not have anything
to do with the running of a container.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5614 from crosbymichael/move-attach-to-daemon

Move Attach from container to daemon
Use the correct "it's."
Merge pull request #5601 from crosbymichael/alex-maintainer

Add alex as devmapper and btrfs maintainer
Add alex as devmapper and btrfs maintainer
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
add linked containers to hosts file

Docker-DCO-1.1-Signed-off-by: Bryan Murphy <bmurphy1976@gmail.com> (github: bmurphy1976)

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Tested-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Simplify integration test for link + hostname.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Merge pull request #5056 by Bryan Murphy <bmurphy1976@gmail.com>

"add linked containers to hosts file"
Add code for Pardot implementation to docs

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Update the run --net cli help to include the 'host' option

and then add that to the run and cli docs

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Merge pull request #5616 from nirvdrum/patch-2

Use the contraction for "it is."
pkg: networkfs: etchosts: fixed tests

This patch fixes the fact that the tests for pkg/networkfs/etchosts
couldn't build due to syntax errors.

Docker-DCO-1.1-Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
integration-cli: docker_cli_links: fixed broken tests

The tests weren't ... tested when last edited, this patch fixes
them so that they run and pass correctly.

Docker-DCO-1.1-Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
Remove support for MemoryReservation in systemd systems. This has been
deperecated since systemd 208.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
Merge pull request #5626 from cyphar/networkfs-etchosts-tests

Fixed broken tests for pkg/networkfs/etchosts
Merge pull request #5627 from cyphar/integration-cli-fixes

Fixed completely broken integration-cli tests
Merge pull request #5629 from vmarmol/fix-systemd-softlimit

Remove support for MemoryReservation in systemd systems.
Merge pull request #5630 from rjnagal/libcontainer-fixes

Check supplied hostname before using it.
Export cpuacct CPU usage in total cores over the sampled period.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
registry: adding vbatts to the MAINTAINERS

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