LANG-951: Fragments are wrong by 1 day when using fragment YEAR or MONTH - applying patch provided by Sebastian Götz, several tests now fail because of wrong assertions, will fix them in a separate commit

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@1559780 13f79535-47bb-0310-9956-ffa450edef68