database.py: add two field into table --  rank and review
main.py: add a variable to represent current page, on reading or finish read
main.py: finish function of presentation_combo, can set list with books on reading or finish read
dlgfinish.py: add a dialog to rank a book when finish button pressed. UI finished.
dlgfinish.py: implement functions.
add book finished info(rank, review, finished time, etc.) into database.
main.py: split UIs to two different ones, one for on reading, one for finished readed. But not seccussful. Run in wrong manner. Need fix.