Ability to add individual events to subscriptions

[jaredbriskman]

After conversation with @HALtheWise , it seems there could be a need to have subscriptions be not only labels based, but have individual events in them.

This is intended to supports the use case of wanting to have a single event added to a subscription without having all of the other things in the label added, e.g. Wanting to add a FWOP perfornace to your calendar, without adding all FWOP rehersals, or even other showings of the FWOP performance.

Current abe-web UX would require a unique label for each FWOP performance, this seems suboptimal.

There was some discussion around having a personal label that isn't displayed, vs having a list of event IDs, each with tradeoffs. This might be better once we have a user model.

Implementation in ABE would then allow for user facing UX in abe-web.

[osteele]

Displaying an event ICS in the web UI would solve a subset of this. The user of a desktop or mobile Calendar User Agent could click on the event icon to open it in their agent, adding it to their personal calendar.

The cases this doesn't cover are:

• Automatically updating their local copy of the event from ABE. The event is copied, not subscribed: the user would need to visit the page and click on the icon again, to refresh it.
• Use with a web calendar (GCal)