refactor breadcrumbs
merged article refactor in and resolved conflicts
go with the functional style
merged in master, formatted code
lowercase links and tidy pre pull-request issues
remove extraneous match case
fixed merge conflicts in content
remove redundant class names from templates
don't lowercase tag links
remove extraneous class to fix align
Merge pull request #4363 from guardian/seo-breadcrumbs-refactor

Seo breadcrumbs refactor