host-deploy: new registration interface

Introduce structured registration interface, based on query string
parameters.

Sadly, we could not reach consensus for removing this legacy interface
in favor of using the public supported rest api of the engine.

Unlike legacy interface, new registration interface supports all
services within single URI.

version
	0: Legacy is missing version field, version is 0.
	1: Current version.

VERSION 0

vds_ip
	Host address to register.

port
	VDSM port within host.

vds_name
	Host name.

vds_unique_id
	Unique id of host.

Returns:
	Timestamp.

VERSION 1

command==get-version
	Get most up to date interface version.

	Returns:
		Content-Type: text-plain
		Content: version

command==get-pki-trust

	Returns:
		Internal PEM encoded CA certificate.

command==get-ssh-trust

	Returns:
		Engine ssh public key.

command==register

	address
		Host address to register, default request origin.

	sshPort
		SSH port within host, default 22.

	sshUser
		SSH user to use.

	vdsPort
		VDSM port within host, default 54321.

	name
		Host name default address.

	uniqueId
		Unique id of host.

	Returns:
		'OK'

Change-Id: I54abaa8a46ac8821374e40c41d1e97a40e04ab1f
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>