Make mapping controller specs pass again
Make helper specs pass again

There are some quite horrible things here, but at the moment I'm just
trying to get all the specs passing again. When I get onto the features
I'll have more of an idea about which helpers we actually need, and
will revisit this to make the helpers better.
Make the mapping index feature pass again

Also update two fixture steps which are also used in other features.
Make mapping filter feature pass again

Also update a fixture step which is used in several other features.
Make the mapping edit feature pass again

The specs for the ToggleMappingFormFields js module were not being
run because the filename didn't end 'spec.js', and after renaming
the file I found that 4 of those tests were failing (on master as
well as on this branch). I've updated the tests so that they look
ore up-to-date, but they are still failing and the output from
rake jasmine:ci isn't very helpful.
Make mapping_create_multiple feature pass again

And also hits_all as a side-effect.
Make mapping_edit_multiple feature pass again

All features and specs are now passing, and the only remaining
failing test is the javascript one which was already broken.
Make the ToggleMappingFormFields js spec pass

With thanks to @fofr. Everything is now green!
Simplify operation_name mappings helper method
Clear out http_status from batches

- remove http_status method from MappingsBatchEntry
- use batch.type instead of batch.http_status for confirmation heading
Check mapping type to display current hit status
Find example mappings by type for glossary
Tidy up remaining http_statuses in mapping model spec
Remove unused data attribute from mappings table
Use mapping.type in hits and mappings feature
Add a test for http_status being set from type on batches

Also add comments explaining why http_status is left the same if it
isn't supported.
Migrate http_status data to type in a migration

- Also support rolling back, to populate http_status from type
- Remove the rake task and its tests
- Also set type on batches as well as mappings
Tell PaperTrail to not track changes to http_status

We've temporarily got two fields storing this information, and we
don't want them both to show up on the history tab duplicating
the same change.