New translation fields

New translation post meta fields could be used to add “Translated by” links for localised articles:

![screen shot 2014-08-21 at 14 37 46](https://cloud.githubusercontent.com/assets/105274/3996017/fccf726e-292f-11e4-8fc9-fbfb6cff183f.png)

Config changes are required by Jekyll itself (they have renamed post types).