removed site-cutter class from all the new splash pages. Updated side margins/padding in responsive 'paying through gocardless' page
removed u-center and site-gutter where it appears with site-container.
Updating all heading tags on new splash pages
using class u-size1of3 instead of 4of12 to be consistent with rest of page
switch from & to &amp; in html
Fixing
Merge pull request #166 from gocardless/removing-site-gutter

Removed site-gutter class from all new splash pages - DO NOT MERGE
Fixing conflicts
Fixing places where text was outside tags
Merge pull request #173 from gocardless/checking-headings

Checking headings
Fixing merge conflicts