New engine command: 'wait'
Engine: don't log job stdout to engine stdout (it might be non-text output, for example tar data for 'export'
Engine: 'export' returns a raw archive of a container's filesystem
Engine: convenience http transport for simple remote job execution
Cleanup version introspection

* Unify version checking code into version.go
* Make 'version' available as a job in the engine
* Use simplified version checking code when setting user agent for registry client.
Port 'docker version' to the engine API
Merge pull request #2843 from shykes/engine-job-wait

New engine job:wait
Merge pull request #3146 from jamtur01/linkedits

Some minor cleanup of the Links use document
Fix #1229. Update titles, fix some wrapping.
Make the Ambassador container explicit.
Apply Sven's suggestions.
Merge pull request #3119 from shykes/engine-version

Port 'docker version' to the engine API
Merge pull request #3103 from metalivedev/1229-titleactions

Update "Use" titles to be action-oriented
don't open bind mounted files/dirs to get Stat, use os.Lstat
Merge pull request #3152 from daniel-garcia/3129_dont-open-bindmounted-files

don't open bind mounted files/dirs to get Stat, use os.Lstat
Merge pull request #3113 from shykes/engine-export

Move 'docker export' to the engine API
Help identify you are in a Docker container

Add environment variable:

    container_manager

With a value of "docker".

This will provide a mechanism for tools like Facter
and Ohai to identify that they are running in a Docker
container.

See https://github.com/puppetlabs/facter/pull/563

See http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface/.

Thanks to Paul Nasrat for the pointer to this.