In Title::resetArticleID(), clear all entries in the LinkCache instead of just the...

In Title::resetArticleID(), clear all entries in the LinkCache instead of just the ones for bad title stuff. resetArticleID() seemed to assume it was only called for titles that come into existance, but that's not correct: it's also called for titles that go out of existence, and titles whose redirect status changes. Noticed this because $nt->getRedirect()'s return value was wrong in my TitleMoveComplete hook.