Pass cobrand into send_email_cron when sending SendReport emails

Without this, email sending within a cobrand will get the right main
email template (submit.txt) for the email - because it uses the
cobrand inside get_template - but it doesn't use the cobrand for
things like the email signature, because you have to pass it into
send_email_cron manually to make it cobrand-aware.

This probably hasn't been noticed before because most cobrands are
called Something FixMyStreet, but Collideoscope is different and hence
it caused a problem there.

Closes mysociety/FixMyStreet-Commercial#621.
Fix encoding of signature in emails.

This text was being imported encoded, which led to double-encoding when
used in templates. Fixes #960 and #961.
Set DefaultLocale appropriately when language set.
Add Open311 i18n test, and add utf8 pragma.

Also remove some unused variables.
[fixmystreet.com] New posters page layout/content.
New UK specific FAQ, more generic base FAQ.

Fixes #753 and #935.
Hide unneeded heading on default footer.
[WIP] [DansMonQwat] Initial CSS.
[DansMonQwat] Add phone number to front page.
[WIP] Locale update from Transifex.