Reverse the dependency for mediawiki.language.data
* Previously mediawiki.language.data depended on mediawiki.language,
making any module using langauge data having to explicitly define
it as a dependency. This is not good. We should abstract the data
generation part and for the users of the module.
mediawiki.language should take care of having the required data.
* So, reversing the dependency so that mediawiki.language depends on
mediawiki.language.data. Then a simple dependency declaration with
"mediawiki.language" is enough to have associated data available.
This supersedes change set I810fb0a5
Change-Id: Iede836bb3e2fd700cb7c58caeebe9ec2e0043dfb