Added time.formats.{blog, friendly} translation keys under ignore_unused in i18n-tasks.yml since used on numerous places for formatting dates / times, removed site.sidebar.close because started being used at 3a51160 and ended being used at 6adcce4, removed sessions.new.title because started being used at f18baae and has been used only in test/system/issues_test.rb (from which we removed it because tests are always in EN)