add scss partial for history-list
add new policy change style to /history
add classes to target the action sentence inside a chage
indent change action sentence(s) on policy change listing
refactor /history changes list
move history page logic from view into controller
move policy history logic from view into controller
move history list into own partial
use history list partial on policy history (refactor only)
cleanup double spaces in helper
add missing full stop to create policy sentence
add tests for version_sentence_no_attribution