Validation of manual title

This introduces the basic plumbing for the validation using the `json-schema` gem.
Outside of Rails (ok, excepting Bouncer), I generally tend to make explicit dependencies by `require`ing, well, what I require. Inside Rails's's bizarre omakase universe, I tend to just let Rails's's's's startup 'require's take care of it for me. IMO `require` practices are not such a black art in vanilla Ruby, but Rails's's's's's's preference for less noise in everything contrive to make them so.