Adding new cards to tag keywords page.
Remove currently unused classes
Remove tests which test Play CRSF system

It's a little redundant to test Play Framework features unless there's
special justification for doing so.
Merge master
Class identifies snappable items. Increase height to 250px.
fix front on-page description HTML render
Refactor authentication ActionBuilders [#MEM-403]

The basic cookie-based authentication is now wrapped by Play's
AuthenticatedBuilder rather than our own code, and the
authentication-backed-by-Identity-API lookup is now composed with this and
an ActionRefiner that does the API-lookup.

AuthActionTest removed because it's effectively testing
AuthenticatedBuilder now, which is tested within Play:

https://github.com/playframework/playframework/blob/9b33c199a/framework/src/play-integration-test/src/test/scala/play/it/auth/SecuritySpec.scala#L15

Play's AuthenticatedBuilder is also used elsewhere in the Frontend project
for the Admin app:

https://github.com/guardian/frontend/blob/3ee4896/admin/app/controllers/IndexController.scala#L17

https://jira.gutools.co.uk/browse/MEM-403
Combine NonThreaded controller into Comments controller
inline comment timestamp
Update test data
Fix issue with date header on wide breakpoint with page skin
Do not use useful mix in anymore :'(
change comment relative date format
add comment permalink icon
Test updated to look for new slices.
missing semicolon
Discussion js app unthreaded support
Log out refreshing of config agent and add endpoing to FaciaController
Add _agentcontents to routes in facia
Discussion linting