Allows us to manage additional speakers from the admin (#58)

* Allows us to manage additional speakers from the admin

* Show speaker e-mail addresses. Fixes #57

* Denotes fields as required.

Fixes for 20160718 (#54)

* Simple form input fields now use TakeFlight styling

* Styles the form widgets as per the styles in our CSS

* Styling of TextArea now matches the remaining input types

* Adds is_last modifier to navigation dropdown

* Adds admin for talk, tutorial, and miniconf proposals

* Adds an RSS feed

* Adds a link to the RSS page

* Unbreaks the old news index page

* Adds never_cache to the login page, removes the never cache middleware from the settings