- [grunt] removed `path.source.data` path, since it won't work anyway inside js function
- [grunt] moved nunjucks old data into new `data` global object
- [grunt] added oftenly used `data.currentYear`
- [nj] replaced current year in layout with `data.currentYear`
- [grunt] external data example moved inside `data.data` and renamed to `test`
- [nj] updated index page with data examples
- [misc] replaced spaces with tabs in `test.json` data-file