S4 signup form: templates should be (extended) HTML, not XHTML.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>
subscription_signup.js: consistent 4-space indentation.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>
subscription_signup.js: delete a stray comma.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>
S4 signup form: make the PGP key field a textarea.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>
S4 signup form: show what to do if the form doesn't load.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>
Kill full_signup processes after 2 hours.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>