Update archive/tar vendored

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Add test for invalid tarball read

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Adding test case for symlink causes infinit loop, reproduces: dotcloud#5370

normally symlinks are created as either
ln -s /path/existing /path/new-name
or
cd /path && ln -s ./existing new-name

but one can create it this way
cd /path && ln -s existing new-name

this drives FollowSymlinkInScope into infinite loop

Docker-DCO-1.1-Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com> (github: lalyos)
Defend against infinite loop when following symlinks

ideally it should never reach it, but there was already multiple issues with infinite loop
at following symlinks. this fixes hanging unit tests

Docker-DCO-1.1-Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com> (github: lalyos)
Fixes 5370 infinite/maxLoopCount loop for relative symlinks

use path.IsAbs() instead of checking if first char is '/'

Docker-DCO-1.1-Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com> (github: lalyos)
Merge pull request #5823 from proppy/archive-bufio

archive: use bufio for compression detection
allow 2 docker events to be opened on the same computer over unix socket

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Update the cli.md docs with the output of the docker command

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #5732 from SvenDowideit/pr_out_the_last_remaining_raw_github_com_url_s

the last remaining raw.github.com URL's
Merge pull request #5802 from shykes/pr_out_add_licensing_information_to_readme

Add Licensing information to README
Merge pull request #5461 from SvenDowideit/getmaintainers.sh
Merge pull request #5454 from kzys/utime-omit

UTIME_OMIT is only available on Linux
Merge pull request #5497 from alexlarsson/generic-driver-tests

graphdriver: Add generic test framework for graph drivers
Change libcontainer to drop all capabilities by default. Only keeps
those that were specified in the config. This commit also explicitly
adds a set of capabilities that we were silently not dropping and were
assumed by the tests.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
Refactor b.tar -> busybox.tar

The file was saved as busybox.tar, but the ls commands named it b.tar.

Docker-DCO-1.1-Signed-off-by: Steven Burgess <steven.a.burgess@hotmail.com> (github: stevenburgess)
Update ubuntulinux.md

In Ubuntu 14.04, we should use

    $ sudo service docker.io restart

instead of

    $ sudo service docker restart
devicemapper: Remove non-general tests

Now that we have the generic graphtest tests that actually tests
the driver we can remove the old mock-using tests. Almost all of
these tests were disabled anyway, and the four remaining ones
didn't really test much while at the same time being really
fragile and making the rest of the code more complex due to
the mocking setup.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #5828 from SvenDowideit/pr_out_update_the_cli_md_docs_with_the_output_of_the_docker_command

Update the cli.md docs with the output of the docker command
Typo in execdrivers.go five => give

Docker-DCO-1.1-Signed-off-by: Timothy Hobbs <timothyhobbs@seznam.cz> (github: timthelion)
nsinit.Init() restores parent death signal before exec

Docker-DCO-1.1-Signed-off-by: Bernerd Schaefer <bj.schaefer@gmail.com> (github: bernerdschaefer)