Unified api

Since most of the foundation plugins depend on a simple "show/hide" mechanism, it'll be easier to have a unified `FoundationApi` object. This object currently houses a simple `pub/sub` system that can be accessed by any element as long as it's specified as a dependency.

The prototype works with the modal currently but it should not be difficult to make it work with the rest of the plugins subsequently. I might be able to abstract even the subscribe/publish system within the directives (possibly).

Outside of that, we now have a namespace and a service we can use to tie in more foundation components! :)

(Don't mind the *extra* file changes. I based this branch off the Modal branch).

**EDIT** I decided to change the implementation a bit. Now it's a true pub/sub system with multiple subscribers and multiple publishers able to communicate. This is great for adding multiple hooks.