Correct a few translation strings

They weren't using dicts for parameters to work around the ordering
issue.
Transifex update
Update AUTHORS file

Using *secret" formula for who's a contributor
Add mailmap file to identify users with different email/names

This is useful for git shortlog - see:
http://simonharrer.wordpress.com/tag/git-shortlog/
Slight reorganisation of sandbox settings
Update CSS docs (they were stale in places)

Fixes #709
Update manage.py files from sandbox and demo

They were copies of an old Django 1.3 project version with some Tangent
extensions.
Add a stub DATABASES setting to bypass a South init issue

Without this, South was choking as it couldn't find a 'default' key in
DATABASES.
Remove bad settings path
Correct offers fixture

Use blank instead of null.
Document how to build the demo site
Update the docs on building the demo site
Remove facet translation from default settings

Since variables were required to be passed in, this forced evaluation of
the i18n string which caused a circular reference when Django started
up.

This isn't a permanent solution - just a workaround until search gets
the a reworking.
Document how to load countries as part of getting set up
Whitespace!
Convert absolute path of webfonts into relative one

So that it's possible to use a different URL for static assets.
Change compressor settings to fix relative URL issue

When the LESS files are served but compression is disabled, the relative
URL between the generated CSS and other assets is wrong (using the
default compressor settings).  This fixes changes the output directory
name to match the path of Oscar's assets, which fixes this issue.

Related to https://github.com/jezdez/django_compressor/issues/226

Fixes #649