Unroll Article::__call again

Unroll Article::__call again

Adds all public functions from WikiPage to Article

Adds all public functions from WikiFilePage that
are not in Article to ImagePage

WikiCategoryPage has no methods that need moving

Removed __call from Article

If extensions extend WikiPage and rely on the __call
method in Article they may break with this change.
They cal easily call $article->getPage()->method..

Change-Id: I8cd8d69d0d59c67f4879212535206688387bead4