Correct TarSum benchmarks: 9kTar and 9kTarGzip

These two cases did not actually read the same content with each iteration
of the benchmark. After the first read, the buffer was consumed. This patch
corrects this by using a bytes.Reader and seeking to the beginning of the
buffer at the beginning of each iteration.

Unfortunately, this benchmark was not actually as fast as we believed. But
the new results do bring its results closer to those of the other benchmarks.

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
Update libcontainer to 53eca435e63db58b06cf796d3a9

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Note that using -lxc-conf to change things Docker manages has pitfalls

Signed-off-by: Sven Dowideit <SvenDowideit@docker.com>

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
Correctly close generated benchmark archives

Another update to TarSum tests, this patch fixes an issue where
the benchmarks were generating archives incorrectly by not closing
the tarWriter.

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
I was talking to someone whom i listen to, and she noted that our docs don't mention the license

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>
Merge pull request #9528 from SvenDowideit/add-license-to-docs

Add Apache license and link to the docs
Merge pull request #9493 from SvenDowideit/note-lxc-conf-pitfall

Note that using -lxc-conf to change things Docker manages has pitfalls
Merge pull request #9488 from crosbymichael/update-libcontainer-dec3

Update libcontainer to 53eca435e63db58b06cf796d3a9
Merge pull request #9479 from jlhawn/tarsum_test_fix

Correct TarSum benchmarks: 9kTar and 9kTarGzip
Removed race condition
If two interrupts were fired really quickly interruptCount could have been incremented twice before the LoadUint32 making cleanup not being called at all.

Signed-off-by: Erik Dubbelboer <erik@dubbelboer.com>
Merge pull request #9543 from ErikDubbelboer/racefix

Removed race condition