Feature/revised/riak cli handoff status 1239

Implement "riak-admin handoff summary" and "riak-admin handoff details [--node=<node>] [--all]"
No idea - that was actually in the code long before we touched it, but emacs reformatted some things and it ended up moving that line.
Generally, I'm guessing it's to be explicit about "I know there's a return value, but I don't care" but I also don't know if that's idiomatic Erlang (or Riak Erlang, or what).