Misleading {TRIGGER.STATUS} value in notifications

The {TRIGGER.STATUS} macro is used in default notifications to display the current status of the problem (trigger). This can be misleading in the case of multiple problem events and event correlation - the corresponding event might have been already resolved while trigger still having problem status.

To solve this we must:

• change {EVENT.VALUE}, {EVENT.STATUS} macros to return problem value if the original event is still in problem state, and ok value if the original event has been resolved (this must work for trigger and internal events).
• replace {TRIGGER.STATUS} with {EVENT.STATUS} in notifications

The {EVENT.RECOVERY.VALUE}, {EVENT.RECOVERY.STATUS} macros are pointless - they always returns OK value, so they can be marked as deprecated.