Implement start, stop and restart methods.

Once we had agreed on the restart logic, the simplest thing to do was to generate the all methods based on that logic.

TODO: Add stop-sleep-start methods.
The `enable` method has one extra option not used by any other, and that is `-r` to recursively enable any dependencies, e.g. `svcadm enable -r <service>`.  CAF should allow us to use that.