Bootstrapification

Boot custom CSS, and put some base, standard css in its place.
Shame I did not start with fresh Bootstrap4, but oh well.

Some more templates could be made to make this less messy, which would
be good.

Adds registration to the website (#69)

* Updates settings and requirements

* First pass at attendee profile

* Imports the registration templates; defines attendee profile models etc.

* First pass at themeing the registration form.

* First page of the registration form: done!

* Makes form validation nicer

* Adds populate_inventory

* Improves the additional items page

* Allows for rendering of formsets.

* Adds support for formset extending.

* Removes formset delete buttons

* Review page is LCA-ified

* Fixes some formset behaviour

* Fixes urls.py

* LCA-ifies product_category.html

* Invoices

* Credit card payments

* s/register/tickets/

* Show registration features only whilst products are available (think about this better, later)

* Updates the attendee profile form page

* Form tidy-up

* Makes it so that address info is copied from attendee profile to the address details are autofilled in Stripe.

* Adds feature to offer Australians a dropdown list of states rather than free text.

* Allow toggling of void invoices.

* Adds backgrounds to the headers in the registration process

* Improves the review page

* Adds “Linux Australia” to invoice details.

* Do not show balance due on void/refunded invoices.

* More thumbing

* Adds a link back to reports on each report.

* Tokenisation language.

* Another bug in credit card processing.

* Adds stripe refunds to options

* Removes spurious dashboard button.

* Tidies up the presentation of discounts.

* Tidies up presentation of voucher form.

* Fixes sponsor logo appearance with adblock.

* Front page tweaks

* Lets us specify alternative URLs in homepage panels

* more

* Updates discount amounts.

* More website fixes

* Changes language on pay invoice button

* Adds contact details to the invoice template.

* Updates the currency message in the invoice template.

* Explicitly includes e-mail address, because theme_contact_email doesn’t propagate

* Changes payment text.

* s/registration/selections/

* Removes final face palm

* Fixes lack of speaker dinner tickets for actual presenters.

* Adjusts wording in invoice e-mails

* Invoice wording.

* (FIX)

* Fixes margins on lists and tables

* Improvements arising from those CSS fixes.

* Changes description tags.

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