Handle / & /wiki & /wiki/ URLs

https://wikia-inc.atlassian.net/browse/HG-438

It probably needs some beautyfing and I could use your suggestions.
A few more things:
* Needs whitespace after function name `handleArticleLoaded (`
* I think this is an awkward function name. IMHO, I think a few better options are: `onArticleResponse`, `handleArticleResponse`, etc.., the word "load" has a different, potentially confusing, connotation for me.