This commit cuts out the structure for defining grpc services for this
project. To provide compatibility with go package generation and support
reuse, we use a single protobuf file per package and make the import
paths relative to the GOPATH.
This first pass attempts to position the Mount type as the lingua franca
of ContainerKit. The Images service will provide paths prepared for use
as a set of mounts of the container service.
We'll need to merge the container service in place with new file defined
here.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
