Chris Willman Music WriterWho says you can’t teach a classic-rock superstar new-media tricks? Paul McCartney seems to be taking some tips from Taylor Swift, in using visual iconography on social media to drop clues about an upcoming project, as she often has. In his case, it would seem, from all indications, to herald the release of a “McCartney III” album.If the hints indeed lead there, “McCartney III” will be following hot on the heels of “McCartney II,” which came out in 1980.