v1.1.3

This is the complete fix. v1.1.1 and v1.1.2 were earlier, partial attempts
at the same bug — deleting a book did not actually remove it — released one
layer at a time when they should have been a single version. Upgrade straight
here from v1.1.0; the earlier two need no separate attention.

The three layers were: the delete could not remove a format that existed only
as a request (v1.1.1); it left the book in Audiobookshelf, which the next
library sync then re-imported (v1.1.2 asked ABS to rescan); and ABS marks a
missing item rather than deleting it, so the sync had to learn to ignore that
flag (v1.1.3).

---

What's Changed

• Stop sync recreating a book ABS has flagged as missing by @Bothari in #29

Full Changelog: v1.1.2...v1.1.3