Comments default to "on" and mobile design improvements

This release includes changes to comments and design changes for desktop and mobile.

• Comments default now set to "on" when new blog or news page is created.
• On major mobile devices, iPhone, iPad and Pixel, site menu, external links and intranet switcher button appear laid out correctly with appropriate spacing.
• Added new agency emails to email whitelist. They can now leave comments and sign in.

Bugs fixed:

• Date not appearing if two or more posts shared the same date on the same page.
• Guidance pages duplicate text. Added additional logic so that excerpt only displays with excerpt field is populated on a page.
• Fixed date issue on single news page. Column sort was incorrect.
• Fixed banner on homepage to now crop rather then resize. This will improve homepage loading/performance.