[Mediawiki-i18n] Changes to PLURAL rules

[Federico Leva (Nemo)]

This went under the radar for a few days, but MediaWiki 1.20wmf11 
brought some major changes to plural handling, thanks to the new CLDR 
plural parser. Careful release notes reader could have spotted it here: 
https://www.mediawiki.org/wiki/MediaWiki_1.20/wmf11 (core changes).
Niklas has just added some (hopefully temporary) overrides to restore 
the old behaviour and fix https://bugzilla.wikimedia.org/40251 : you 
should report on the bug if your language has the same problem.
<https://translatewiki.net/wiki/Plural/Comparison_of_plural_rules_in_various_databases> 
lists the differences between CLDR and MediaWiki rules and
<https://translatewiki.net/wiki/Thread:Support/PLURAL_keyword_for_languages_without_grammatical_plural_forms> 
has some more discussion.

Nemo

P.s.: 1.20wmf11 has been enabled everywhere on the 12th and the switched 
on and off a few times on en.wiki but it seems it will stay now despite 
some other bugs, check [[Special:Version]].