Updating B2D upgrade instructions for 1.2.0.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
add the [OPTIONS] string automatically if there are flags defined

Signed-off-by: SvenDowideit <SvenDowideit@home.org.au>

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #7766 from fredlf/update_b2d_upgrading

Updating B2D upgrade instructions for 1.2.0.
move TestKillDifferentUser

Signed-off-by: Victor Vieux <vieux@docker.com>
Merge pull request #7708 from SvenDowideit/programatic-usage-options

add the [OPTIONS] string automatically if there are flags defined
move TestEntrypoint & TestBindMounts

Signed-off-by: Victor Vieux <vieux@docker.com>
remove auth_test.go

Signed-off-by: Victor Vieux <vieux@docker.com>
Merge pull request #7767 from vieux/move_some_tests

Move some tests
Update /etc/hosts when linked container is restarted

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
pkg/graphdb: tests for Parents and Children

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
pkg/networkfs/etchosts: tests for Update method

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Update networking doc with clarified text regarding links usage

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)