devmapper: Maks createSnapDevice a function, not a method

No idea why this was a method. Maybe a cut and paste bug.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Move error detection to devmapper.go

This moves the EBUSY detection to devmapper.go, and then returns
a real ErrBusy that deviceset uses.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Simplify thin pool device id allocation

Instead of globally keeping track of the free device ids we just
start from 0 each run and handle EEXIST error and try the next one.

This way we don't need any global state for the device ids, which
means we can read device metadata lazily. This is important for
multi-process use of the backend.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Store metadata in one file per device

This allows multiple instances of the backend in different containers
to access devices (although generally only one can modify/create them).

Any old metadata is converted on the first run.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Adding Rohit Jnagal and Victor Marmol to pkg/cgroups maintainers.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
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)
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)
Fix logo in README.md
Merge pull request #5631 from vmarmol/cpuacct-usage

Export cpuacct CPU usage in total cores over the sampled period.
Merge pull request #5622 from SvenDowideit/net-host-docs

Update the run --net cli help to include the 'host' option
use tabwriter to display usage in mflag

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
improve some usages

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
update the docs to reflect the nice \n handling

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
Set container pid for process in native driver
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5643 from crosbymichael/fix-native-pid

Set container pid for process in native driver
Merge branch 'master' into bump_v0.11.0

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4 from SvenDowideit/improve_mflag_usage_docs

update the docs for the new \n rendering
Merge pull request #5634 from vieux/improve_mflag_usage

Add support for \n in usages
The Go template is a better pattern for documentation.
mkimage-debootstrap: set ubuntuLatestLTS as Trusty

Ubuntu 14.04 LTS (Trusty Tahr) was released on Thu, 17 Apr 2014; Update
ubuntuLatestLTS accordingly.

Docker-DCO-1.1-Signed-off-by: Jonathan McCrohan <jmccrohan@gmail.com> (github: jmccrohan)