nanny: Destroy ifworkers of removed policy
ifup: Add ni_ifup_start_policies() for cleanup
Revert "server: no unrequested device-ready events (bnc#871135)"

This reverts commit f44606d1678d2a7411b7b27c20fa166214a8ce02.
fsm: Update workers name if device has been renamed
nanny: Do not reset workers upon configuration
nanny: Perform recheck in controlled manner

Recheck only in case of:
- DEVICE_READY event
- ifworker is not done nor failed
nanny: Start FSM only in case of ifworkers to recheck on
fsm: Tune ni_ifworker_complete()

Does not check for target_state as factory workers
may not been started but still uncompleted.
Export the function.
fsm: Add ni_ifworker_is_factory_device() function

This function is supposed to tell whether ifworker
reflects factory device not created yet.
nanny: Factory device handling by nanny

- Perform ni_fsm_build_hierarchy() only upon
  new ifworker arrival
- Do not destroy recheck array each time
- Clean recheck upon device delete event
- Schedule non-existing factory devices