Start of JWT token based authentication BOOK-560

- updated the templates to work with some changes in BB - verbatim to hbs partials
- added auth action to use the token based authentication introduced in the following BB PR:

https://github.com/onepercentclub/bluebottle/pull/642

So far login and logout is working. The jwtToken isn't being stored client side so the user won't remain logged in after a page reload, or after changing language. Guess we can store this in a cookie or in html5 store.

We also need to look at what we do in ember app initialisers because these won't triggered when the user logs in.