Recurrence exceptions have weird behavior where a 'recurrence exception' can be treated
as the root of a recurrence sequence, by appending, for example, /2 to the uri.
https://phabricator.wikimedia.org/E196 is recurrence 2 of https://phabricator.wikimedia.org/E179
but if you visit https://phabricator.wikimedia.org/E196/3 you get a ghost event that appears to
be a recurrence of E196.
I think more consistent behavior would be to treat E196/3 as recurrence
3 of E179 which makes it possible to easily navigate through a series even when some of the
events are ghosts and others are recurrence exceptions, etc.
How I've addressed the problem
- For recurring sequences, base the sequence start date on the original event instead of the "recurrence exception" instance.
- Added simple navigation buttons for next/previous recurrence.