Timeseries chart x-axis labels should be show in UTC when the user selects that preference

[nblumhardt]

Dashboard x-axis labels should show UTC dates and times when this preference is set (this also applies to the "as timeseries" view in the Events screen).

[nblumhardt]

It's 5:30 pm on June 8th where I am currently in GMT + 10h (Brisbane). Here's "Show timestamps in UTC":

And here's local time:

Note that x-axis tick formatting is still limited in control over 12/24 hour time. Always more to do another day :-)