Uptime Feature

[sapiderman]

So a monitoring dashboard will need some kind of Uptime calculcation I think.

Since for symon, up and down events are based on incidents and recoveries from Monika probes, we can calculate

downtime: TimeRecovered - TimeOfIncident
Therefore: Total Uptime = Total_time_monitored - Total_downtime.

If we can get just the data for 24 hours, total time for a week is just the daily summation of the uptime down times.

poke: @kevin-hyperjump

edited: typo