Version bump and changelog for 0.16.1

changes/changelog.d/478.bugfix

-Removed release date error in case of empty date (#478)

changes/changelog.d/487.bugfix

-Fixed typos in scheduled tasks configuration (#487)

changes/changelog.d/488.bugfix

-Display public playlists properly for anonymous users (#488)

changes/changelog.d/new-languages.i18n

-Added portuguese, spanish and german translations

changes/changelog.d/webpack.enhancement

-Simpler configuration and toolchain for the front-end using vue-cli (!375)