Everything has broken since this last ran. This commit fixes a few
obvious things but the whole Vagrant thing needs some attention.

At least until this PR is merged
https://github.com/sorl/sorl-thumbnail/pull/167

The CSV importer is one of three equally broken ones in the repo.
Nonetheless, it's rather slow due to lack of not happening in a
transaction. This one-liner speeds it up by factor of two.

* Analogous to 64b59f the default cache for the demo site has been
  switched to LocMemCache instead of memcache
* Comments regarding usable databases have been updated
* The language code has been changed to en-gb

Most sandbox deployments probably run in the development server and
won't benefit of a shared cache. LocMemCache is the sensible choice as
it doesn't require external dependencies and it seems like it might even
be slightly faster as there's no connection overhead.

It has been considerably improved and doesn't cause any significant
performance hit anymore. Hence, it's been enabled by default again.

@maikhoepfel also took the opportunity to re-order the DDT panels.

Fixes #820

We currently mention it in internals/sandbox.rst. I've added a note to
the dashboard app (ref/apps/dashboard.rst), the sandbox/urls.py and
expanded on the feature explanation on index.rst.

Fixes #816

To avoid duplicate log messages

This change handles the backwards compatiblity issue of adding a
required stockrecord field onto the basket line model.

When a basket in encountered which has a line without a stockrecord, we
delete it and attempt to re-add it to the basket.

We also merge the middleware together for simplicity.

- Add setting for demo
- Correct typo for sandbox

Dependencies installed via setup.py stay in their eggs and their
templates won't be found by Django. This caused a
TemplateNotFoundError when users were trying to use
Django's admin to set categories.
Using the admin is unsupported, but this still prevents a similar error
from happening when we use other dependencies that ship templates. It
also shouldn't slow down production use.

Fixes #761

Hmmm, this turned out to be a monster commit.  This change allows the
basket to be able to correctly calculate prices including tax.

It also requires a whole load of test changes since all baskets now
require a strategy instance to be assigned.

# Last 5 commit messages
# ----------------------
# a52aaec Docs: Document how to create migrations # Last 5 commit messages # ---------------------- # 30eead5 Remove custom user app from sandbox [Maik Hoepfel] # ee3ee02 Drop create_migration.py helper [Maik Hoepfel] # a77e78c Don't show country field if only one is available [David Winterbottom] # b5790aa Handle products without a category in GA subission [David Winterbottom] # 39e0932 Merge pull request #782 from tangentlabs/feature/add_eway_extension_to_docs [David Winterbottom] [Maik Hoepfel]
# 30eead5 Remove custom user app from sandbox [Maik Hoepfel]
# ee3ee02 Drop create_migration.py helper [Maik Hoepfel]
# a77e78c Don't show country field if only one is available [David Winterbottom]
# b5790aa Handle products without a category in GA subission [David Winterbottom]

This is to keep the sandbox as vanilla as possible, as it's the
environment that migrations should be built against.

...as it slows the page load down to a crawl.

This is responsible for picking the appropriate strategy class for the
session and assigning it to the request.

The strategy class then is responsbile for returning the appropriate
price and availability wrappers for a given product.

A template tag is responsible for calling the strategy class with the
product to get the appropriate wrappers needed in the template.

I used the existing script [1] that cooperates very nicely with vim.
1: https://github.com/rory/django-template-i18n-lint

Fixes #676

- Only handles Datacash payments at the moment