add --releasever=/ to mkimage-yum.sh

I didn't realize the commit required a Docker-DCO so it failed the travis-ci build. So I removed the commit from my forked repo. Now it looks like there is a pull request with no commit. So here it is again:

Needed to add '--releasever=/' flag to run yum groupinstall on Centos7 (didn't try on anything else). This snippet from yum man page explains why:

```
Note: You may also want to use the option --releasever=/ when creating the installroot as otherwise the $releasever value is taken from the rpmdb within the installroot (and thus.  will  be  empty,  before  creation).
```

Docker-DCO-1.1-Signed-off-by: Matt Schurenko <matt.schurenko@gmail.com> (github: mschurenko)
Adding self to various maintainers files.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Implementing IPv6 functionality for ipallocator

Closes #6975

Signed-off-by: Malte Janduda <mail@janduda.net>
docker save: Do not save to a terminal.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
install.sh: Fix for Amazon's Linux AMI

Use /etc/os-release to determine distro

Contents of /etc/os-release on Amazon Linux AMI 2014.09:
NAME="Amazon Linux AMI"
VERSION="2014.09"
ID="amzn"
ID_LIKE="rhel fedora"
VERSION_ID="2014.09"
PRETTY_NAME="Amazon Linux AMI 2014.09"
ANSI_COLOR="0;33"
CPE_NAME="cpe:/o:amazon:linux:2014.09:ga"
HOME_URL="http://aws.amazon.com/amazon-linux-ami/"

Signed-off-by: Amit Bakshi <ambakshi@gmail.com>
Signed-off-by: Jessica Frazelle <jess@docker.com>
check ID in os-release instead

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Return container exit code with start -a/-i
Addresses #8555

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>
Clean up comment sections and fix typos in CmdRun

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
small typo
Use dual-stack Dialer when talking to registy

Signed-off-by: Gleb M. Borisov <borisov.gleb@gmail.com>
Link to run reference from cli doc

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
Fix typo

Signed-off-by: Zach Borboa <zachborboa@gmail.com>
DOCKER_VERSION and docker-version havn't been implemented.

So far, it looks like the declarations are not used, and so its safer not to
confuse people into thinking they do something.

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
daemon: resolve the graphdriver to show

graphdriver is not always specified when the log printed, because
it's provided in another thread. This patch will fix this.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
fix cli dashes in boot2docker resizing article

The CLI commands had long dashes that won't work on most terminals when copy pasting.

Signed-off-by: wilsaj <wilson.andrew.j+github@gmail.com>
Update container linking documentation

As of 1.3 `docker ps` no longer shows links between containers.
This updates the documentation to reflect that change.

    sudo docker docker inspect -f "{{ .HostConfig.Links }}" web

Signed-off-by: Philipp Weissensteiner <mail@philippweissensteiner.com>
builder: handle cases where onbuild is not uppercase.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Merge pull request #8684 from erikh/onbuild_case_insensitive

builder: handle cases where onbuild is not uppercase.
Fix racy integration tests

Do not run containers in the background in the integration tests if you
depend on the run completing.  It is better especially if you just want
to ensure that the run has completed with a `true` to just run in
foreground and use a known name for the container to query it after it
has stopped.

The failures can be reproduced on most machines by giving your dind
container one core and a cpushare.

docker run -c 200 --cpuset 0 -ti --rm --privileged -e
DOCKER_GRAPHDRIVER=vfs docker hack/make.sh binary test-integration-cli

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Merge pull request #8661 from estesp/8555-start-exit-code

Return container exit code with start -a/-i