Hg 91 top nav bar

**DO NOT MERGE**

@hakubo @kenkouot 

This is the branch for the Wikia nav menu -- you tap the icon to the left of the Wikia icon, and it slides out. Currently, search is not functioning so tapping it or typing into it may throw errors, but navigation should work.

TODO for navigation: add sliding menus, touch states
TODO for search: implement node-side search api, get it to work with our Ember search MVC
This string needs to be internationalized