Add schema.org microdata

Based off a conversation with @psd, wanted to add a little extra to our
output.

Longer term, this should be moved into the data model and reflected in
the API as well as markup.

Placeholder for a future conversation.
Merge pull request #870 from alphagov/feature/schema.org-annotations

Add schema.org microdata
Add big screen link to overview and detailed dashboards only
Merge pull request #871 from alphagov/big-screen-link

Add big screen link to overview and detailed dashboards only
Make big screen link absolute

Big screen is hosted on a different domain, so a relative link
returns a 404.
Merge pull request #872 from alphagov/big-screen-absolute-link

Make big screen link absolute
Big screen link - add subheading / change link text as per updated design
Merge pull request #873 from alphagov/big-screen-link

Big screen link - add subheading / change link text as per updated design
User sat graphs should be more configurable

In order to migrate the user_satisfaction_graph module over to using
transformed data we need more control over the keys that the module uses
to pull data out of records.

This also rewrites the gathering of a breakdown to use the axes rather
than a hard coded list of labels.

The migrated property is to skip the application of query parameters and
parsing that is required for dealing with the untransformed data.
Merge pull request #874 from alphagov/feature/user-sat-options

User sat graphs should be more configurable
User totalAttr to pull out total responses

totalAttr looked like to should be used to define which key would derive
the total response from. This was not actually being used in the
function and the totalRatings key exists no where. I have now defaulted
it to the correct field name and used it where it is appropriate.
Merge pull request #875 from alphagov/feature/user-sat-options

User totalAttr to pull out total responses