fixes #416
Merge branch 'develop' into pr/417

Conflicts:
	securedrop/source_templates/howto-disable-js.html
	securedrop/source_templates/index.html

Also removed links and just put the text of the URLs in the body text in
howto-disable-js.html, since we no longer have the redirect hack to
avoid leaking the referrer for visited links.
Merge branch 'pr/417' into develop