Kill off use of $wgRequest, $wgUser, and $wgLang in SkinTemplate, stop using $out...

Kill off use of $wgRequest, $wgUser, and $wgLang in SkinTemplate, stop using $out args on our protected methods, deprecate the $out on outputPage and for now make it temporarily override the context of the skin (or should we throw a fatal if someone passes an OutputPage that doesn't match context)