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)
devmapper: include dm_deps information in debug

Signed-off-by: Vincent Batts <vbatts@redhat.com>
daemon logging: unifying output and timestamps

A little refactor of the ./pkg/log so engine can have a logger instance

Signed-off-by: Vincent Batts <vbatts@redhat.com>
Fix potential race in volume creation

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
Adding self to various maintainers files.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Add --security-opts options to allow user to customize security configuration

security-opts will allow you to customise the security subsystem.

For example the labeling system like SELinux will run on a container.

    --security-opt="label:user:USER"   : Set the label user for the container
    --security-opt="label:role:ROLE"   : Set the label role for the container
    --security-opt="label:type:TYPE"   : Set the label type for the container
    --security-opt="label:level:LEVEL" : Set the label level for the container
    --security-opt="label:disabled"    : Turn off label confinement for the container

Since we are passing a list of string options instead of a space separated
string of options, I will change function calls to use InitLabels instead of
GenLabels.  Genlabels interface is Depracated.

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)
add apparmor:

Signed-off-by: Victor Vieux <vieux@docker.com>
Move Go() promise-like func from utils to pkg/promise

This is the first of two steps to break the archive package's dependence
on utils so that archive may be moved into pkg.  Also, the `Go()`
function is small, concise, and not specific to the docker internals, so
it is a good candidate for pkg.

Signed-off-by: Rafe Colton <rafael.colton@gmail.com>
Move Matches() file path matching function into pkg/fileutils

This is the second of two steps to break the archive package's
dependence on utils so that archive may be moved into pkg. `Matches()`
is also a good candidate pkg in that it is small, concise, and not
specific to docker internals

Signed-off-by: Rafe Colton <rafael.colton@gmail.com>
Move archive package into pkg/archive

Now that the archive package does not depend on any docker-specific
packages, only those in pkg and vendor, it can be safely moved into pkg.

Signed-off-by: Rafe Colton <rafael.colton@gmail.com>
Prettify docs-update.py

Remove commented code, use format for string concatenation, split long lines, fix how-to-run instructions
Signed-off-by: Davide Ceretti <dav.ceretti@gmail.com>
Add missing "tag" parameter to tag API

Closes #4877

Signed-off-by: Doug Davis <dug@us.ibm.com>
update docs

Signed-off-by: Victor Vieux <vieux@docker.com>
update tests

Signed-off-by: Victor Vieux <vieux@docker.com>
Edits and fixes to Dockerfile Best Practices based on review feedback.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Merge pull request #8299 from vieux/pr_7425

Add --security-opts options to allow user to customize container labels and apparmor profile
Merge pull request #8266 from cpuguy83/fix_race_in_createing_volumes

Fix potential race in volume creation
Create registry_api_client_libraries.md
Signed-off-by: Konrad Kleine <konrad.wilhelm.kleine@gmail.com>
Add registry_api_client_libraries.md to mkdocs.yml

Signed-off-by: Konrad Kleine <konrad.wilhelm.kleine@gmail.com>
Update host_integration.md