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.
Usually we enable/disable services asynchronously and therefore don't send options.  However, when we do want a service to start synchronously, it is often the case that we don't want to specify a timeout with `-T`.  Also bear in mind that the `-T` option is new to Solaris 11.2, and we're still running 11.1 here.  So, we need a way of requesting the `-s` option (i.e. `sync` mode) without having to imply the `-T` option (`timeout`).