* (bug 32686) Tooltip on links to non-existing pages are now always in user's language

* (bug 32686) Tooltip on links to non-existing pages are now always in user's language

Fixed this by "abusing" of the $options parameter of Linker::link() to pass the Language object (as we did for wfMsgExt()), has the two following advantages:
* The tooltip is displayed in the requested language instead of depending on $wgLang
* The usage of the Language object is detected in the ParserOptions, thus the parser cache key will not have "*" for the language