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- Easily specify new outputs from tasks (no need to edit obs_ packages)
- butler.get should fail immediately if the data is not available
- Easily iterate over partial IDs for all dataset types
- Simplify the way IDs are normalized (?), and document the system better; also preferably make it easier to know when you have an ID that has been normalized or not.

Handling of bitemporal calibration products including camera descriptions. N.b. calibration products can be lots of different things: objects, images, telemetry data, etc.