Early version of comparison table
Table looking finished
Fixed spacing of headers, started refactoring towards using more u-classes
First css refactor done
refactor of CSS complete
spacing added for readability in HTML doc
Added table to Pro page. Removed SS-standard font (previously used for icons)
optimised the new SVGs with SVGO
svgo checkmark-icon.svg --pretty --enable=removeTitle

saved about 2 kB total
Pulled the comparison table out into its own include.
Checkmark and cross now accessible.
(Might consider using u-is-hidden-visually in future, with '✓' and '✗' marks - unicode characters 2713 and 2717)
Rename 'u-background-dark-grey-darken' to 'u-background-dark-gray-darken' (grey to gray)
for consistency
Merge branch 'dev' into product-comparison-table

Conflicts:
	app/pages/pricing/index.html
div with unique ID added for Angus to inject with Optimizely
Merge pull request #324 from gocardless/id-for-optimizely

div with unique ID added for Angus to inject with Optimizely
Merge pull request #309 from gocardless/product-comparison-table

New product comparison table added