Add labels to form & aria associations for sections
Refactor CSS structure
Replace step icons with those from toolkit
Correct error in rebased template
Rename validation partial & clean out unused
Tidy up

Add comments to application.scss & corrections to
folder structure
Clean out unused files
Kill info box styles
Reposition adjusted net income box

Also includes fixes for commented issues.
Merge pull request #39 from alphagov/form-markup-changes

Form markup changes