LCA2022 Setup

Update dates and descriptions for LCA2022.
Remove old miniconf proposal types.
Add local timezone to speaker profile.

Finalise registration

Add shirt types and sizes. Improve messaging about discounts.
Restyle ticket wizard and product category screens. Enable page titles
and messages. Update dashboard to hide raffle.
Enable inventory population for dev container.

Update fixtures

Remove fixtures from 2018 and 2019. Add fixtures for 2020.
Cleanup structure of fixtures directory. Update scripts to match.

Add a test fixture which creates a user for testing the CFP

Also add a single proposal which can be reviewed.

Correct variable name to reflect what it's naming

IT's not the container name, it's the image name. Fix the name to be
less confusing.

Improved handling of static/build and css generation

When the container is mounted, the local contents of . obscure
/app/symposion_app in the image.

Generally speaking, this is handy for development, as it means that
local changes are detected and used immediately without needing to
restart the container.

However, it breaks in the specific case of the sass->css
generation. Prior to this change, the css is generated only after the
first time a page is hit. The generated file is placed in
static/build; however, due to the obscuration, this generated file
isn't visible to the running process.

The next time the container is built, the pre-existing static/build
directory is copied into the container as it's being built; then,
later, that version is what gets served.

This change adds the needed libraries to pre-generate the css as part
of the image build, and runs compilescss to do this, prior to the
collectstatic step.

It also adds a second collectstatic into the make_dev_container
script, so that the visible static/build directory should ahve the
same contents as the obscured static/build directory. It also expands
the .dockerignore file to make sure these files aren't copied into the
image in future.

I'm not sure if this is the right thing to do, as changes to this
directory will be ignored, which could be confusing. Perhaps never
being able to see these generated files is better?

Utilise multi-stage docker build for consistent dev/prod base

* developers can use --target symposion_dev to get a responsive site
that reads from their homedir and reacts to changed files instantly
* without a specified target the default is to build the prod image,
which is identical except for running uwsgi instead of the django
built-in server
* Enable debug when running in a developer's test environment
* Remove the makemigrations script and dockerfile

Fix miniconf fixture dates

Some proposalsections were still set to open immediately. Change that
to 1 Nov.

More transparent support for symposion-fixtures dir

symposion-fixtures being a really crappy name for a folder that has
some utility stuff for helping populate a site with dummy data

Revert "Don't populate inventory"

This reverts commit 0d06fc08ebcb029f9003d7d3da4e400dc647d907.

make_dev_container

Expand on support for devs by scripting the process of creating,
starting, and initialising a dev container.

Take container name as an optional parameter

Create a dev docker container for makemigrations

* Adds a laptop-mode-env file which docker can read env variables from
* Adds a Dockerfile.makemigrations; mostly identical to the main
Dockerfile. Important difference: instead of the source being copied
into the docker image at build time, it's mounted from the local
machine at run time.
* Adds a makemigrations shell script which builds an imagine using the
Dockefile.makemigrations and then uses it to run makemigrations
* Because the source is mounted from the local machine, any new
migrations created are dumped in the developer's git checkout ready
for adding to git.

Rename .env -> docker/laptop-mode-env