Backwards incompatible changes:
* Dropped support for Django < 1.11
* Removed the KV registration form system. It proved very unwieldy in practice.
New features:
* Django 2.0 support (although not all of our dependencies do, yet)
* Using bootstrap 4.0.0 final
* A **withdrawn** talk state, differentiating between scheduled talks that were cancelled, and proposals that were retracted.
* A new API to indicated a user's conference registration state to wafer (when not using a built in registration method).
* Dynamic menu infrastructure, including a sponsor dynamic menu.
* ical export of schedule.
* Documentation for:
* Menus.
* Settings.
* Talk management.
* A `wafer/base_form.html` template to simplify media handling for templates with a single form.
Bug Fixes:
* Display better information schedule error states.
* `load_pages` admin command under Python 2.
* Specify `on_delete` behaviours everywhere, as required by Django 2.
* Improve logout page.
* Track last_updated state on Schedule Items.
* Only load JS in the page footer, for browser performance.
* Get markitup widgets rendering everywhere, again.
* Fix SSO links.