Sort courses by `course.id` on course#index
Adds very basic login using Persona/BrowserID.

Squashed commit of the following:

commit 756d55d88dcb87df8be1c406b1f72a70f3da047e
Author: Victor Andrée <hej@victorandree.se>
Date:   Thu Feb 21 14:15:10 2013 +0100

    Basic authentication works. Not authorization yet.

commit d6c2b5af9ee5b51256f7ba48f11d4dc10830fb8b
Merge: b03dd5a 53b966c
Author: Victor Andrée <hej@victorandree.se>
Date:   Thu Feb 21 13:24:39 2013 +0100

    Merge branch 'development' into auth

commit b03dd5acaa1720d9d135862ce57c3588bf26673e
Author: Victor Andrée <hej@victorandree.se>
Date:   Thu Feb 21 13:08:10 2013 +0100

    Adds Express sessions, and root view.

commit dc0f4d46ca1d5121bf7ec7ac35d0137f966453a9
Author: Victor Andrée <hej@victorandree.se>
Date:   Thu Feb 21 13:00:23 2013 +0100

    Adds public folder -- and login button (non-functional)