remove odd </a>
apply missing linebreaks to shipping.notes
use get_model only once
remove redundant and even wrong comments
Replace tax exemptions recipe with a more general US one

Fixes #1266
Merge pull request #1264 from st4lk/small_fix1

Minor template fixes and code refactor
Merge branch 'master' of https://github.com/tangentlabs/django-oscar into project/mr