set all 4 ts on the master-modification (plus doAutoTriageOnDateChange, so 5)

THIS MEANS WE'RE CREATING LOTS OF TRIAGE-STATUS REMINDERS, gotta optimize that

updating triageMods should consider:
 - doAutoTriageOnDateChange 

Update triageMods at:
 - Purge time
 - Time change (thisandfuture or individual)
 - when setTriageStatus is called (override in Occurrence, only do something if it's a real change)
 - no longer needed in observer


------------
Other:

[] If it's not yet done (between start and end) triage as NOW 
[] (and set flag as if reminder fired) if set to Now

[] set triage status in occurrences, don't calculate it, also set doAutoTriageOnDateChange explicitly to True