New method to list containers (with missing parameters)

[gdevillele]

I left the existing "client.ListContainers" method but created a "client. client.ListContainersWithOptions" method.
It does the same thing, but allows 3 additional parameters to be provided : "limit", "since" and "before".
The goal is to have the same options than in the docker CLI.

[donhcd]

I think these options would be nicer as a struct, something like:

type ListContainerOptions struct {
    All, Size bool
    Limit, Since, Before, Filters string
}

[donhcd]

can you also add the new method to the interface in interface.go and to the mock in mockclient/mock.go?