Permutations dropdown for examples

[longrunningprocess]

when working out the display for references, consider organizing them by specific permutations, e.g., examples with an instrument, examples without, by book...

1. need to consider what to do about duplicate chapter:verse keys, e.g., takeA Exodus 21:24
2. add permutations dropdown once the algorithm is worked out

Judges 14:9 => p|A|SamsonA|honeyA||beeA||handA|||

| Agent-like | Patient-like | (Source) | (Destination) | (Instrument) | => 2^3 permutations

					Heading
Agent	Patient				with required only
Agent	Patient	Source			with Source
Agent	Patient	Source	Destination		with Source and Destination
Agent	Patient	Source	Destination	Instrument	with Source, Destination and Instrument
Agent	Patient	Source		Instrument	with Source and Instrument
Agent	Patient		Destination		with Destination
Agent	Patient		Destination	Instrument	with Destination and Instrument
Agent	Patient			Instrument	with Instrument

[longrunningprocess]

I wonder if it makes sense to bring the theta grid out of the main card area and put it under the Examples header... ask some of the users if the theta grid is useful in the "summary" or more applicable in the "details".

[craigp-atw]

After discussion, we decided to try adding a multi-selector (eg checkboxes) for each role of the theta grid above the verse dropdowns - so selecting 'Destination' would cause the dropdowns to only include the examples that contain a 'Destination' argument.

Selecting multiple roles would likely act as an AND filter, but that's not certain.