* Correctly get messages which use the form "mainpage/fr" even if they were not creat...

* Correctly get messages which use the form "mainpage/fr" even if they were not created in the database, but only in the language file. This allows us to specify things like {{int:mainpage/fr}} without creating MediaWiki:Mainpage/fr (as we do in {{int:mainpage}}), and to view the default content of pages like MediaWiki:Mainpage/fr without creating them (as we do in MediaWiki:Mainpage). For this, creating a new static function - Language::getMessageFor - and getting the message for the language with it. This parsing applies only for messages with the "/" symbol (there are no such messages), so it should not break things.
* Because we define the messages 'january-gen', 'february-gen', etc. as the genitive forms of months in Langauge::mMonthGenMsgs, I created them in the English file. This should fix the test of {{CURRENTMONTHNAMEGEN}} in the parser tests (currently seems to output "<january-gen>"), and should fix the wrong output of checkLanguage.php and transstat.php, which think that these messages are obsolete.
* Using the genitive forms of the months in Hebrew
* (bug 6939) Update to Indonesian localisation (id) #31