Wait for pidfile to exist when starting with Redhat init script

Fixes #5359

Docker-DCO-1.1-Signed-off-by: Chris St. Pierre <chris.a.st.pierre@gmail.com> (github: stpierre)
added timeout when waiting for docker pidfile

Docker-DCO-1.1-Signed-off-by: Chris St. Pierre <chris.a.st.pierre@gmail.com> (github: stpierre)
docs: cli.md; document docker version output

Commit 3cec63d56f9de6332aa3f33502695283d4feb054 changed the output of
docker version. Updating docs accordingly.

Docker-DCO-1.1-Signed-off-by: Jonathan McCrohan <jmccrohan@gmail.com> (github: jmccrohan)
Merge pull request #5920 from jmccrohan/master

docs: cli.md; document docker version output
cgroups: Allow mknod for any device in systemd cgroup backend

Without this any container startup fails:
2014/05/20 09:20:36 setup mount namespace copy additional dev nodes mknod fuse operation not permitted

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
native driver: Add required capabilities

We need SETFCAP to be able to mark files as having caps, which is
heavily used by fedora.
See https://github.com/dotcloud/docker/issues/5928

We also need SETPCAP, for instance systemd needs this to set caps
on its childen.

Both of these are safe in the sense that they can never ever
result in a process with a capability not in the bounding set of the
container.

We also add NET_BIND_SERVICE caps, to be able to bind to ports lower
than 1024.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #5844 from stpierre/init-script-wait-for-pidfile

Wait for pidfile to exist when starting with RedHat init script
Merge pull request #5929 from alexlarsson/systemd-cgroup-allow-mknod

cgroups: Allow mknod for any device in systemd cgroup backend
Merge pull request #5930 from alexlarsson/add-cap-setfcap

native driver: Don't drop SETFCAP
Mount /dev in tmpfs for privileged containers
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)