TODO

Export DB in JSON modes
Allow import from calibre
Add responsive mode
    (should allow several books on same row ?)
Allow list of author by letter when a lot of authors are available (forced or by config ?)
Compute small thumbnail of cover (with link to real cover if needed ?) (needed for ebook reader or for low bandwidht connection)
Add Catalog.atom link
Add detection of language on summary
Fix validate unique
Tags are not saved form edit webpage
Order Authors list on edit page (it looks like order by their internal ID)
Improve Author check (suppress whitespaces, try to invert between ',', ...)
Add webpage to perform action on multiple items like add tags or updating authors
Add default 'anonymous' author if not fount in EPUB or in JSON import