ActionFinish called after Action completion

The worker now calls ActionComplete or ActionFailed on state, depending
on the success state of the Action and any errors.

The hook is set to an error state if the Action hook is missing, or if
other errors take place during hook execution.  If the Action hook sets
a fail state, the Hook will not error, rather the Action will fail.

DEPENDS: https://github.com/juju/juju/pull/651
just make this type the anonymous struct you define up at the top and drop the loop-repeatedly stuff -- even with the triple-action-log it's not going to be a problem to see:

    verifyActionResults{
        status: "complete",
        name: "action-log",
    },
    verifyActionResults{
        status: "complete",
        name: "action-log",
    },
    verifyActionResults{
        status: "complete",
        name: "action-log",
    },

...in the tests -- the extra expressivity isn't worth it IMO.