Thursday + Takeflight changes (#31)

* Adds Facebook svg button, and adds Facebook link type to models

* CSS work from takeflight, 30 June 2016

* Adds drop-down menus for navigation

* Adds mobile menus for navigation

* Minor tweak to mobile nav headings

* Makes the logo a link back to the homepage

* Updates the footer to the current version, removing sponsor logos for the moment.

Templates (finished?) (#22)

* Adds inset_illustration as a drop-down of svg data rather than as an uploady thing.

* Adds external link types to the homepage models

* Migrations

* Initial site template with our new shiny templates

* Moves all lca2017-specific assets to lca2017 subdirectory; symlinks from dist

* Reflects changes in site_base

* Deletes most of new assets in dist/

* WIP home page

* Adds external link list support

* Adds white-right panel type to the home page

* Removes an oops

* Adds copyright text to the site.

* Updates the remaining illustrations to be more compact.

* Adds illustration field to content_page, and adds fields into the news page.

* News index page

* News page is done!

* Formats the dates properly

* Commits migrations

* Optimises SVG files

* better logo

* oops

* Removes margin on logo.

* Optimises svgs, and uses tania’s originals

* One more