Better localization support

Created by: nyuwec

In some languages future and past tenses expressed differently. For example in Hungarian "2 days ago" translates to "2 napja", but "in 2 days" translates to "2 nap múlva". As you can see the words must be separated more, please check the implementation is moment.js: https://github.com/moment/moment/blob/develop/locale/en-gb.js It handles singular, plural, past and future as separate cases. But it is far from easy to translate, because as a translator you should understand the javascript code.

I would create a simple "matrix" containing all the strings with placeholders inside, so the translators could freely write the proper sentences.

translations = {
...
'day': {
  'singular': {
    'past': 'one minute ago',
    'future': 'in a minute'
  },
  'plural': {
    'past': '%d minutes ago',
    'future': 'in %d minutes'
  },
...
},

wdyt?