Localisation updates from https://translatewiki.net.
Updated CREDITS file in preparation of 1.2.16 release
Bump version and update release notes for 1.2.16
Changed version to 1.2.17dev [skip ci]
Update copyright year to 2014

Really should have done this before releasing 1.2.16... oh well.
[skip ci]
Fix #16940: undefined function db_params() in news_api.php

Regression introduced by 7efe0175f0853e18ebfacedfd2374c4179028b3f
(fix for issue #16880)
Localisation updates from https://translatewiki.net.