2 - user flags for words and kanji
4 - user notes for words and kanji
5 - hide results with/without user notes
8 ? user added sentences, words
9 - example words for kanji
10 - synchronization of the user database with a newly generated one
11 - export to CSV/HTML/Anki (filtered by flags)
14 - xz compression ( db.v00.gz: 38MB, db.v00.xz: 25 MB)
15 - improve GUI::init_fonts() so it will be not necessary to restart app after
16 some changes to fonts (like selecting a new font or font size)