NEW:
- #91 Date (first) published: the date-picker has been redesigned
- #93 sorting by language now uses the full language name
- #96 translated book language field
- #113 group-level summation of the books in that group.
- local search new UI
- local advanced search now showing the results live
- added filter for identifiers

FIXES:

- #114 crash due to https://issuetracker.google.com/issues/309593253
- #109 sorting by dates on the book level now supports mixing partial-dates
