Build and command enhancements

[johndistasio]

Suggesting some updates here:

1. Add a stats subcommand for the cluster API.
2. Allow for extra args to cluster/state and node/stats for filtering output.
3. Use dep instead of go get. I think Dep is still the closest thing to "the" Go package manager; modules still seem to be a work-in-progress.
4. Use the current import path for the cli package.
5. Change build command to force a static binary.

[rolinh]

Hi @johndistasio,

Thanks you for your contributions; there's a lot of cool stuff in there :)
About 3., yes, I think think that Dep is the closest thing to the "Go package manager" for now, until modules (vgo) has matured.