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)
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)
Fix interactive exec over TLS

The code no longer assumes a net.TCPConn underlying the HTTP connection
in order to close attached streams.

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
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
Merge pull request #9497 from icecrime/86580-tls_interactive_exec

Fix interactive exec over TLS
Changing the windows installation doc to include instructions how to login
using putty instead of CMD

Signed-off-by: Krasimir Georgiev <support@vip-consult.co.uk>
Fixing the puttygen link to point to download page instead of direct download.

Signed-off-by: Krasimir Georgiev <support@vip-consult.co.uk>