Select masquerade by outgoing interface rather than by destination subnet

Docker-DCO-1.1-Signed-off-by: Jérôme Petazzoni <jerome@docker.com> (github: jpetazzo)
Increase size of buffer for signals

The chan struct used to forward signals to containers was one element only,
which caused some signals to be dropped when many were being received.
Increasing the size of the chan buffer makes this much less likely to happen.

Docker-DCO-1.1-Signed-off-by: Matt Heon <mheon@redhat.com> (github: mheon)
Move TestGetImagesByName

Docker-DCO-1.1-Signed-off-by: Adrien Folie <folie.adrien@gmail.com> (github: folieadrien)
add client OS and arch to docker version

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
Moved last build tests to integration-cli

Also removed skipped tests on "viz" and "tree" because they
blocked integration/buildfile_test.go removing.

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Merge pull request #6823 from folieadrien/move_integration_tests

Convert TestGetImagesByName into unit and integration-cli test
Merge pull request #6847 from SvenDowideit/add-os-and-arch-to-docker-version

add client OS and arch to docker version
Merge pull request #6371 from jpetazzo/6370-masquerade

Select masquerade by outgoing interface rather than by destination subne...
Merge pull request #6508 from mheon/signals

Increase size of buffer for signal forwarding with --sig-proxy
Merge pull request #6859 from LK4D4/move_buildfile_tests_to_cli

Moved last build tests to integration-cli