Update/fix build tags, Dockerfile, and release.sh for proper building and releasing of linux/386 and linux/arm cross-compiled client binaries

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Unit test ensuring that a tar.TypeXGlobalHeader does not cause an error

Docker-DCO-1.1-Signed-off-by: Abel Muiño <amuino@gmail.com> (github: amuino)
Ignore tar.TypeXGlobalHeader

Docker-DCO-1.1-Signed-off-by: Abel Muiño <amuino@gmail.com> (github: amuino)
Merge pull request #3800 from vieux/cleanup_jobs

Cleanup jobs
Merge pull request #3866 from crosbymichael/dont-allocate-1

Do not allocate networks first ip
Merge pull request #3861 from metalivedev/fixkerneldeps

Fixed link to kernel dependencies.
Merge pull request #3864 from SvenDowideit/lxc-kill-script-workaround-doc

add a known issue for lxc-1.0.0.beta3 and beyond for removeal of lxc-kil...
Merge pull request #3829 from vieux/fix_api_regression

Fix ID -> Id api
merge master

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #4 from tianon/cross-compile-and-release-linux-i386-and-arm-clients

Update/fix build tags, Dockerfile, and release.sh for proper building and releasing of linux/386 and linux/arm cross-compiled client binaries
Merge pull request #3844 from clkao/lxc-kill-deprecation

Use lxc-stop -k instead of lxc-kill
merge master

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3828 from tianon/add-user-email-to-dockerfile

Add dummy "user.email" setting in our Dockerfile for smooth in-container merge commits
fix panic in mflag

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3857 from creack/remove_darwin_files

Remove all darwin specific files and use more generic _unsupported with build tags.
Merge pull request #3841 from alexlarsson/separate-base-fs

Separate out graphdriver mount and container root
Finish moving networking information into driver

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Update core calls to network drivers

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Fix sending []byte in job env

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Fix integration tests

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)