Sorry, I also didn't know what we need to do here. I am still not sure, but I have ideas.
Unfortunately the list above was not complete – it looks like there are 172 messages to translate. We do not use them all in DiscussionTools, but we will probably want them all for CLDR.
'century-one' => '{0} century',
'century-other' => '{0} centuries',
'day-future-one' => 'in {0} day',
'day-future-other' => 'in {0} days',
'day-one' => '{0} day',
'day-other' => '{0} days',
'day-past-one' => '{0} day ago',
'day-past-other' => '{0} days ago',
'day-short-future-one' => 'in {0} day',
'day-short-future-other' => 'in {0} days',
'day-short-past-one' => '{0} day ago',
'day-short-past-other' => '{0} days ago',
'decade-one' => '{0} decade',
'decade-other' => '{0} decades',
'fri-future-one' => 'in {0} Friday',
'fri-future-other' => 'in {0} Fridays',
'fri-narrow-future-one' => 'in {0} F',
'fri-narrow-future-other' => 'in {0} F',
'fri-narrow-past-one' => '{0} F ago',
'fri-narrow-past-other' => '{0} F ago',
'fri-past-one' => '{0} Friday ago',
'fri-past-other' => '{0} Fridays ago',
'fri-short-future-one' => 'in {0} Fri.',
'fri-short-future-other' => 'in {0} Fri.',
'fri-short-past-one' => '{0} Fri. ago',
'fri-short-past-other' => '{0} Fri. ago',
'hour-future-one' => 'in {0} hour',
'hour-future-other' => 'in {0} hours',
'hour-one' => '{0} hour',
'hour-other' => '{0} hours',
'hour-past-one' => '{0} hour ago',
'hour-past-other' => '{0} hours ago',
'hour-short-future-one' => 'in {0} hr.',
'hour-short-future-other' => 'in {0} hr.',
'hour-short-past-one' => '{0} hr. ago',
'hour-short-past-other' => '{0} hr. ago',
'microsecond-one' => '{0} microsecond',
'microsecond-other' => '{0} microseconds',
'millisecond-one' => '{0} millisecond',
'millisecond-other' => '{0} milliseconds',
'minute-future-one' => 'in {0} minute',
'minute-future-other' => 'in {0} minutes',
'minute-one' => '{0} minute',
'minute-other' => '{0} minutes',
'minute-past-one' => '{0} minute ago',
'minute-past-other' => '{0} minutes ago',
'minute-short-future-one' => 'in {0} min.',
'minute-short-future-other' => 'in {0} min.',
'minute-short-past-one' => '{0} min. ago',
'minute-short-past-other' => '{0} min. ago',
'mon-future-one' => 'in {0} Monday',
'mon-future-other' => 'in {0} Mondays',
'mon-narrow-future-one' => 'in {0} M',
'mon-narrow-future-other' => 'in {0} M',
'mon-narrow-past-one' => '{0} M ago',
'mon-narrow-past-other' => '{0} M ago',
'mon-past-one' => '{0} Monday ago',
'mon-past-other' => '{0} Mondays ago',
'mon-short-future-one' => 'in {0} Mon.',
'mon-short-future-other' => 'in {0} Mon.',
'mon-short-past-one' => '{0} Mon. ago',
'mon-short-past-other' => '{0} Mon. ago',
'month-future-one' => 'in {0} month',
'month-future-other' => 'in {0} months',
'month-one' => '{0} month',
'month-other' => '{0} months',
'month-past-one' => '{0} month ago',
'month-past-other' => '{0} months ago',
'month-short-future-one' => 'in {0} mo.',
'month-short-future-other' => 'in {0} mo.',
'month-short-past-one' => '{0} mo. ago',
'month-short-past-other' => '{0} mo. ago',
'nanosecond-one' => '{0} nanosecond',
'nanosecond-other' => '{0} nanoseconds',
'quarter-future-one' => 'in {0} quarter',
'quarter-future-other' => 'in {0} quarters',
'quarter-past-one' => '{0} quarter ago',
'quarter-past-other' => '{0} quarters ago',
'quarter-short-future-one' => 'in {0} qtr.',
'quarter-short-future-other' => 'in {0} qtrs.',
'quarter-short-past-one' => '{0} qtr. ago',
'quarter-short-past-other' => '{0} qtrs. ago',
'sat-future-one' => 'in {0} Saturday',
'sat-future-other' => 'in {0} Saturdays',
'sat-narrow-future-one' => 'in {0} Sa',
'sat-narrow-future-other' => 'in {0} Sa',
'sat-narrow-past-one' => '{0} Sa ago',
'sat-narrow-past-other' => '{0} Sa ago',
'sat-past-one' => '{0} Saturday ago',
'sat-past-other' => '{0} Saturdays ago',
'sat-short-future-one' => 'in {0} Sat.',
'sat-short-future-other' => 'in {0} Sat.',
'sat-short-past-one' => '{0} Sat. ago',
'sat-short-past-other' => '{0} Sat. ago',
'second-future-one' => 'in {0} second',
'second-future-other' => 'in {0} seconds',
'second-one' => '{0} second',
'second-other' => '{0} seconds',
'second-past-one' => '{0} second ago',
'second-past-other' => '{0} seconds ago',
'second-short-future-one' => 'in {0} sec.',
'second-short-future-other' => 'in {0} sec.',
'second-short-past-one' => '{0} sec. ago',
'second-short-past-other' => '{0} sec. ago',
'sun-future-one' => 'in {0} Sunday',
'sun-future-other' => 'in {0} Sundays',
'sun-narrow-future-one' => 'in {0} Su',
'sun-narrow-future-other' => 'in {0} Su',
'sun-narrow-past-one' => '{0} Su ago',
'sun-narrow-past-other' => '{0} Su ago',
'sun-past-one' => '{0} Sunday ago',
'sun-past-other' => '{0} Sundays ago',
'sun-short-future-one' => 'in {0} Sun.',
'sun-short-future-other' => 'in {0} Sun.',
'sun-short-past-one' => '{0} Sun. ago',
'sun-short-past-other' => '{0} Sun. ago',
'thu-future-one' => 'in {0} Thursday',
'thu-future-other' => 'in {0} Thursdays',
'thu-narrow-future-one' => 'in {0} Th',
'thu-narrow-future-other' => 'in {0} Th',
'thu-narrow-past-one' => '{0} Th ago',
'thu-narrow-past-other' => '{0} Th ago',
'thu-past-one' => '{0} Thursday ago',
'thu-past-other' => '{0} Thursdays ago',
'thu-short-future-one' => 'in {0} Thu.',
'thu-short-future-other' => 'in {0} Thu.',
'thu-short-past-one' => '{0} Thu. ago',
'thu-short-past-other' => '{0} Thu. ago',
'tue-future-one' => 'in {0} Tuesday',
'tue-future-other' => 'in {0} Tuesdays',
'tue-narrow-future-one' => 'in {0} Tu',
'tue-narrow-future-other' => 'in {0} Tu',
'tue-narrow-past-one' => '{0} Tu ago',
'tue-narrow-past-other' => '{0} Tu ago',
'tue-past-one' => '{0} Tuesday ago',
'tue-past-other' => '{0} Tuesdays ago',
'tue-short-future-one' => 'in {0} Tue.',
'tue-short-future-other' => 'in {0} Tue.',
'tue-short-past-one' => '{0} Tue. ago',
'tue-short-past-other' => '{0} Tue. ago',
'wed-future-one' => 'in {0} Wednesday',
'wed-future-other' => 'in {0} Wednesdays',
'wed-narrow-future-one' => 'in {0} W',
'wed-narrow-future-other' => 'in {0} W',
'wed-narrow-past-one' => '{0} W ago',
'wed-narrow-past-other' => '{0} W ago',
'wed-past-one' => '{0} Wednesday ago',
'wed-past-other' => '{0} Wednesdays ago',
'wed-short-future-one' => 'in {0} Wed.',
'wed-short-future-other' => 'in {0} Wed.',
'wed-short-past-one' => '{0} Wed. ago',
'wed-short-past-other' => '{0} Wed. ago',
'week-future-one' => 'in {0} week',
'week-future-other' => 'in {0} weeks',
'week-one' => '{0} week',
'week-other' => '{0} weeks',
'week-past-one' => '{0} week ago',
'week-past-other' => '{0} weeks ago',
'week-short-future-one' => 'in {0} wk.',
'week-short-future-other' => 'in {0} wk.',
'week-short-past-one' => '{0} wk. ago',
'week-short-past-other' => '{0} wk. ago',
'year-future-one' => 'in {0} year',
'year-future-other' => 'in {0} years',
'year-one' => '{0} year',
'year-other' => '{0} years',
'year-past-one' => '{0} year ago',
'year-past-other' => '{0} years ago',
'year-short-future-one' => 'in {0} yr.',
'year-short-future-other' => 'in {0} yr.',
'year-short-past-one' => '{0} yr. ago',
'year-short-past-other' => '{0} yr. ago',