Styleguide: Remove properties section since it has been moved to TTK styleguide
Styleguide: Minor changes on imports
License cleanups
Cleanups
Docs: Change command to rebuild assets after customization
Docs cleanup: Use code-block
Docs: Include a note about building the assets in the installation docs

If installing directly from the sources, without running these commands
Pootle won't run given the default configuration created by `pootle init`.
Cleanup: Store middleware in a single place
Styleguide: Guidelines for defining fields in models and forms
Cleanup: Add some sections on styleguide

This will ease providing links to specific sections when referring to Pootle
styleguide.
Revert "Prevent Firefox from attempting to install the XPI"

This reverts commit 1d39a08282ef5385affc431810372bf66cdfa2ee.

This fixes serving files from extension actions. I didn’t understand
what I was doing back then; the redirect() is needed because it is a
special URL handled in pootle/urls.py to serve the files with
django.views.static.serve, so using normal HttpResponse() meant I was
sending the browser a text string not the actual file!

The issue of Firefox trying to install the XPI file instead of
downloading it remains unsolved.
Prevent Firefox from attempting to install the XPI

Instead of redirecting to the '/export/' URL, use a regular
HttpResponse() to serve the contents of the file with proper
Content-Disposition set.
Fix leftovers of tp.overview

It was renamed to pootle-tp-overview in
945069d6a5fa08b8b3d9d144ce4c34289d355d92.