cli: new daemon command and new cli package
cli: new daemon command and new cli package

This patch creates a new cli package that allows to combine both client
and daemon commands (there is only one daemon command: docker daemon).

The `-d` and `--daemon` top-level flags are deprecated and a special
message is added to prompt the user to use `docker daemon`.

Providing top-level daemon-specific flags for client commands result
in an error message prompting the user to use `docker daemon`.

This patch does not break any old but correct usages.

This also makes `-d` and `--daemon` flags, as well as the `daemon`
command illegal in client-only binaries.

Signed-off-by: Tibor Vass <3f1326dff4d85ad4ec938fb33f64575ace96db26@docker.com>

docker/go-connections