Revert r36093 (bug 14404).

Revert r36093 (bug 14404).

Regressions caused by this:
"Use an anonymous user to get the parser options and the parser cache key, thus wikitext rendering is not depending of some sepcific user options such as lang, ..."

User-specific options such as stub threshold were still applying in the parser, but not taken into account in the parser hash key. As a result, the caches were corrupt, saving different options into the anonymous-default options cache.