[reboot-proposal] Service setter

[Yomguithereal]

The setter service option seems to be missing from the reboot. I don't remember if it was by design or not.

controller.registerService({
  url: '/users',
  setter: 'users'
});

Same thing as

controller.registerService({
  url: '/users',
  success: function(data) {
    this.update('users', data);
  }
});

The option is short to write and kinda handy. However, the setter name is not that good. Maybe we can find something better if we want to keep this option.

[jacomyal]

Yup, not sure if it was in the design either, but it still looks like a good idea.