events setup crashes on time with sub seconds

[osteele]

The event list at/views/board and /views/events should be sorted by date.

Multiday events should be sorted as though their start date were max(event.start, now.start_of_day).

[osteele]

The actual issue was that one of the events ("Infrastructure Workshop Course Exhibition", May 12–17, id=5aecfb808c031300180f75f4) had an end date with sub-second accuracy (2018-05-17 03:59:59.999000), that Date.parse can't handle.

I've added a workaround to truncate the subseconds. (Not rounding, just because it's easier and I don't know where the fix should really go.)