Ratings should not be created with a GET

[dread]

Background

In the Web UI, when you rate a package it simply links to something like:

​http://ckan.net/package/rate/mke-liquor-licenses?rating=3

This creates a GET request.

This is bad because:

• Search engine crawlers follow links to find pages, and in this case end up creating a rating (although we've got a robots.txt to try and avoid this)
• There are occasions when we want to make a CKAN instance read-only, so we put a <LimitExcept? GET> Apache instruction in. But the database may still get written for these ratings.
• Best practise for web requests is for GET to be a read-only request.

[rgrp]

Rating are currently disabled (invisible) so moving this down.

[thejimmyg]

This ticket is more than 6 months old so marking as invalid in line with out ticketing policy.