We do not need all data here, this is only an 'helper' repo for building, reference one
remains SVN bf-translations one.

This commit:
    * Removes all files not needed for final translations building.
    * Makes remaining files much lighter by removing any non-translated/fuzzy/commented
      messages, as well as all comments.

Removing all comments will also dramatically reduce the diff size on updates, since
most of the differences typically comes from changes in ':src:' comments (line numbers).

From now on, git i18n repo will be updated weekly, on same basis as svn trunk.