Event order logic

[artisanchurch]

Base rule:

Events should appear in chronological order, i.e., from happening soonest to happening latest.

But events that occur on/across multiple dates throw a wrench into this mix.

Temporary way to solve this:

• [x] Create a date date field (in addition) to the open text human-readable date field we have now) Actually, the existing event_start_date field works fine.
• [x] Set posts to sort by the new date event_start_date field

And the maintainer will have to manually adjust when long-running events need to appear lower than a later, but higher-priority, event.

[artisanchurch]

This work is complete and live.