do not alter json in docker save

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
improve test

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
add a test using the flags

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
More verbose error for parallel pull

Partially fixes #6484
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Validate that one of streams choosen in logs on api side

Fixes #6506

There is the bug, that very hard to fix: When we return job.Errorf in
"logs" job it writes to job.Stderr, to which connected ResponseWriter and on
this write w.WriteHeader(http.StatusOK) is called. So, we get 200 on error
from "logs" job.

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Fix minor typo

Docker-DCO-1.1-Signed-off-by: Kevin Houdebert kevin.houdebert@gmail.com (github: qwazerty)
Disable netgo for dynbinary builds

It's not necessary to use the netgo implementation for non-static builds. :)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
docker save: raw json

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Merge pull request #6503 from LK4D4/verbose_parallel_error_pull_#6484

More verbose error for parallel pull
Merge pull request #6516 from LK4D4/validate_logs_params

Validate that one of streams choosen in logs on api side
Merge pull request #6571 from vbatts/vbatts-raw_json

raw json for `docker save`
Fix minor typo and improve wording
Clean up some uses on 'an' in builder docs
Merge pull request #6529 from qwazerty/master

Fix minor typo
Merge pull request #6553 from tianon/disable-netgo-for-dynbinary

Disable netgo for dynbinary builds
Merge pull request #6578 from ch3pjw/documentation_fix

Fix minor typo and improve wording
Implement tail for docker logs

Fixes #4330
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)