wording tweaks
replace london image with kings place image
add new image
Merge pull request #9 from guardian/image-consistency

Image consistency
update text after PR discussion
Merge pull request #6 from guardian/homepage-wording

wording tweaks
Improve the registration page:
 * Display developer and commercial differences side by side
 * Display forms only when user has selected a tiers
 * Link to the appropriate page ob mastery if the user has a mashery account