Bug 913686: Listings

HTML, CSS, JS and image assets for listings pages. 

deploy.py is still being pushed as changed. I don't know why and can't seem to rebase to fix it. Will need to be excluded from merge.

Changes which could affect all pages:
Added text to <button> elements on all pages.
Changed specificity of .cta so it could be applied to buttons as well as anchors.
Added text-decoration: none to a:hover globally.