Put old page size back after tests that set it
Remove page size set now we're restoring defaults

* We fixed badly-behaved tests mutating page size state
  and making downstream tests fail. That means this test
  doesn't need to concern itself with setting it.
Add tag button to mappings table

* Display only, currently non functional
Monkey-patches (to our own classes, no less)

* To avoid deprecation warnings or other nonsense caused by gem clashes
No-JS bulk tagging of existing mappings

* We subvert the purpose of params[:http_status], allowing 'tag'
* We use a BulkTagger class with the same interface as BulkEditor
BulkTagger existing mapping behaviour should:

* Remove common tags removed from tags field
* Add or ensure presence of other tags
* Leave non-common tags alone
Let steps know via @_javascript if they're JS
Bulk tagging via JS modal

* still abusing http_status as a 'tag' vehicle
Stop abusing http_status. Rename to "operation"