Requests to start a service and retrieve it's port on success. 
- Parameters
 - 
  
    | client | The lockdownd client  | 
    | identifier | The identifier of the service to start  | 
    | service | The service descriptor on success or NULL on failure | 
  
   
- Returns
 - LOCKDOWN_E_SUCCESS on success, LOCKDOWN_E_INVALID_ARG if a parameter is NULL, LOCKDOWN_E_INVALID_SERVICE if the requested service is not known by the device, LOCKDOWN_E_START_SERVICE_FAILED if the service could not be started by the device