Add mailing list signup.
Add format to basket params.
Compress email images
More small fixes.

- Add persona to frame CSP to fix login in Nightly.
- Remove static profile template.
- Make image links in user emails absolute.
- Make privacy policy checkbox required via HTML5 attributes.
- Fix broken tests from basket PR.
- Fix issue with disabling cancel button on video form.
Home page about section, director videos