fix docker login

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3872 from crosbymichael/network-driver

Remove networking out of core and into a driver
fix api with old version

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3882 from vieux/fix_compat_api

fix api with old version
Merge pull request #3880 from vieux/fix_docker_login

fix docker login
Do not generate all numberic truncated ids

Fixes #3869
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #3868 from 1uptalent/3867-allow-pax-global-extended-headers-to-passthrough

FIX 3867 allow pax global extended headers to passthrough
Fixes #3879 by updating embedding of ascii.io (now asciinema.io)
Docker-DCO-1.1-Signed-off-by: Andy Rothfusz <github@developersupport.net> (github: metalivedev)
Merge pull request #3881 from crosbymichael/no-all-number

Do not generate all numberic truncated ids
Merge pull request #3832 from jlhawn/3831-auth-tests-server-address

Prevent Tests from creating users on Prod Index
Move UserLookup functionality into a separate pkg/user submodule that implements proper parsing of /etc/passwd and /etc/group, and use that to add support for "docker run -u user:group" and for getting supplementary groups (if ":group" is not specified)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Use type switch instead of reflection

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Consolidate a bunch of the supplementary-groups tests to cut down on the number of RUN lines in a single Dockerfile within TestBuild

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
docker: detect defaultNetworkMtu from default route

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: google)
Remove reference to <linux/btrfs.h>, and instead use <btrfs/ioctl.h> like we're supposed to (from btrfs-progs)

This fixes compilation issues when btrfs.h isn't available (because we just need the relevant structs, which for userspace programs are supposed to come from btrfs-progs instead of the kernel headers).

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Update PACKAGERS.md to explicitly talk about stripping, quoting Dave Cheney from Golang upstream (who is very, very adamant about not stripping Golang compiled binaries)

While there, remove the now-outdated section about `CGO_ENABLED=0`

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Fix docker commit output

The id is returned as Id, not ID, so print the right thing.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #3899 from tianon/do-not-strip-binaries

Update PACKAGERS.md to explicitly talk about stripping
Fix several btrfs driver error messages

Several of the error messages were wrong, but not one of them was helpful, so this fixes them to include the important information (the actual error), and a correct description of which operation failed.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #3892 from tianon/remove-btrfs-header-reference

Remove reference to <linux/btrfs.h>, and instead use <btrfs/ioctl.h> like we're supposed to (from btrfs-progs)