Synchronization of secondary objectives

There is an issue with secondary objectives - when svar sync for that objective is on, new value may be overridden with previous value. Without sync it will never update.

In Footprints of Phantoms (10082) there are 2 hostages; rescuing them with sync off counts only for rescuer. Sync on - inconsistent results.

Possible solution - call our own sync var implementation from lua on important events.