- It is now easier to override hard-coded assumptions, and an alternate parameter format (with ParamBag first) is supported.

- Removed the API item check from getRequestGroups since it doesn’t return anything useful when item-level holds are not allowed.
- Switched item existence check and item availability check to subqueries so that they wouldn’t all apply to the same location when a request group contains multiple locations.

- Use checkbox-select-all’s form attribute if it exists and the closest form only if it doesn’t. Make sure to update checked state of any other select-all checkbox when one changes state.