feat: removed the requirejs dependency

I'm using the window.famous object from their global build as you suggested.
If you want to distribute your own version of the famous lib, I've managed to generate my own version using browserify-ftw and browserify, but it seems to be a little less clean (they probably use custom parameters).

For the moment I've kept the same function calls by registering the famous lib in the same `_modules` hash that we were using for requirejs. The difference with the global famous object is that we use slashes instead of dots.

For example `$famous["famous/utilities/Utility"]` is the equivalent of `window.famous.famous.utilities.Utility`.
I do what I want!