Use the default strings of timeago.js for timeago
Use the default strings of timeago.js for timeago tooltips.
Note: during migrating from jQuery.timeago to timeago.js in !6274 (merged), partial replacement happened. jQuery.timeago's strings are available at https://github.com/rmm5t/jquery-timeago/blob/v1.5.3/locales/jquery.timeago.en.js