- Use cursorMark for fetching IDs in sitemap generator search mode (faster for large indexes).
- Simplify code to better separate retrieval mode-specific logic.
- Change default retrieval mode to "search" since "terms" may not behave as expected in some situations (e.g. when hidden filters are applied).

- See also VUFIND-1308

- Also restructures display to better adapt to missing data fields and for easier customization/extensibility.

- Security: do not pass the user's existing password back into the template; instead, leave the password field blank and check credentials only when it is changed.
- Bug fix: when the user updates an active library card, update the user table as well as the library_cards table.
- Bug fix: when the active library card contains invalid credentials, allow the user to either log back in with good credentials or switch to a different card.

This avoids invalid identifiers from being indexed. Example: "WX 35" catalogued in the ISSN field and can be found with search term "Linux".

- We should not assume ils-none means no holdings; a use case exists where a user has no real-time ILS but still encodes holding information in MARC records.
- We should actually check whether getHolding returns data to determine whether holdings exist.
- TODO: consider introducing a local record driver cache if performance issues are encountered (but probably not necessary).

- Automatically creates and configures standard VuFind plugins
- Either uses an existing factory or creates a stub for building one

- Derived from the work of Fabio Chagas da Silva, Rodrigo Garcia and Roland Keck.

- Includes a bug fix to the status lookup code that was performing unnecessary duplicate work.

Signed-off-by: Stefan Weil <sw@weilnetz.de>