Add mention of mounting cgroupfs properly to PACKAGERS.md

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge branch 'master' of github.com:dotcloud/docker
Move installmirrors anchor in doc

so it's before "Mirrors" instead of "Docker and local DNS server
warnings"

Docker-DCO-1.1-Signed-off-by: Marc Abramowitz <msabramo@gmail.com> (github: msabramo)
Remove hard coding of SELinux labels on systems without proper selinux policy.

If a system is configured for SELinux but does not know about docker or
containers, then we want the transitions of the policy to work.  Hard coding
the labels causes docker to break on older Fedora and RHEL systems

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)
In certain cases, setting the process label will not happen.

When the code attempts to set the ProcessLabel, it checks if SELinux Is
enabled.  We have seen a case with some of our patches where the code
is fooled by the container to think that SELinux is not enabled.  Calling
label.Init before setting up the rest of the container, tells the library that
SELinux is enabled and everything works fine.

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)
docs: explain what docker run -a does

This adds a bit of documentation for the `-a` flag for docker run.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #4953 from rhatdan/selinux

These two patches should fix problems we see with running docker in the wild.
Merge pull request #4972 from unclejack/document_a_flag

docs: explain what docker run -a does
Merge pull request #4924 from msabramo/move_installmirrors_anchor_in_docs

Move installmirrors anchor in doc
docs: Fix typo in hello world example
explained what authConfig actually is.

Docker-DCO-1.1-Signed-off-by: Michael Neale <michael.neale@gmail.com> (github: michaelneale)
Merge pull request #4985 from drothlis/patch-1

docs: Fix typo in hello world example
Merge pull request #4984 from michaelneale/master

explained what authConfig actually is