Simplifies /people intro

closes #479
Set policy_id on create as well
Add a separate list of the vote changes made
Merge multiple changes into one sentence and factor out common bits
Combine two lists into one
Add links and factor out common bits
Add a link to the history page in some silly places
An alternative way we could combine things for ticket #479
Federal -> Australian. More specific and no extra words
Merge pull request #480 from openaustralia/simplify_people_intro

Simplifies /people intro
Extract methods
rename method
Inline method
Show percentages consistently
Oops. the contents of two columns was the wrong way around
Inline partial
Move action to different controller
Combine two controller actions into one
Rename parameter in url
Small refactor