Implements the v1/library/tags set of endpoints to sync CalibreWeb
shelves with the Kobo device.
Drive-by: Refactors shelf.py to consolidate how user permissions are checked.
Drive-by: Fix issue with the sync endpoint that arrises when a book is
hard-deleted.
Better output on upload cover
Fix for download after access to opds/fileformat
Fix osd search link
Added ratings to opds feed
Change for kobo sync for testing
Fixes from tests
Fix response opds with read/unread
changed db_reconnect
Changed output for error 500 (now including error message)
Fix in task queue after 20 messages
Ozzieisaacs