The only visible change is a better tolerance with options (-ld6 is
accepted for -l -d 6).

Use DESTDIR and prefix with their usual meaning.
Change destdir default from /usr/local to /usr.
Drop trailing whitespaces.
Encode in UTF-8.
Drop obsolete TODO list.
Update VCS URL.
Handle 'q' key without a separate task.
Rewrite call of C functions.
Manpage: sort options, update options, improve formatting.