Add database_cleaner since js tests can't use transactions

Don't clean the config table since that gets populated on init, it seems
like
Add one big js smoke test for editing pages
Html_safe the error proc in the generator

There's a corresponding change in trusty_blank for this.
Fixing password edit js

And, uh, deleting the pending test we had for this since we talked about
only having like one big js test, and, uh, i can't get it working
Be quiet when we're running tests, Rack::Cache!!